Football

Conditioning

What is Stretching?

Stretching is the process used to elongate muscles for optimal functioning of the body in sports and everyday life. This elongation can happen with no movement as in static stretching, with movement as in dynamic stretching. I even take stretching further. If we include dynamic stretching and warm up we then must understand that it wakes up muscles and warms up the body as well. The most common types of stretches are:

• Static Stretching
• Dynamic Stretching
• Foam Rolling (self myofacial release)
• Active isolated stretching
• Neuromuscular stretching

For the purposes of this article we will discuss in the greatest detail static stretching while dynamic stretching and foam rolling will be discussed briefly.

Benefits of Stretching

Stretching should be incorporated and taken seriously as part of a regular strength and conditioning program. New methods of stretching and understanding have taken us to higher levels of implementation. With that as a background here are some of the benefits of stretching.

Injury Prevention

There is some debate in the science community as to whether stretching before activity actually reduces injury. One study from 2004 reviewed the impact of stretching on sports injury risk. They reviewed various other studies relating to stretching and concluded there is not sufficient evidence to either endorse or discontinue a stretching routine before and after exercise. ([1] Fradkin AJ, 2006)

I have seen it mentioned multiple times in the scientific literature that there is insufficient evidence to suggest stretching reduces injuries. But don't let this debate fool you. There's got to be something to stretching even if some studies or reviews show otherwise. Can you imagine the sports world without stretching? I cannot. And even if some studies showed no injury prevention benefit from stretching, who in their right mind would have the guts to keep their athletes from doing it. It would be irresponsible to stop stretching.

From time to time you will come across information on CNN or Fox News quoting the "newest study" on stretching. For example, just the other day my brother heard a study from a news source that showed no difference in injuries between the group that stretched and did not stretch. The study went on to say the real injury difference comes from switching between the two. In other words, it is when you switch from stretching to not stretching or not stretching to stretching that causes the problem. I have not read the research so I can fully comment on it. But I would add this; if you are not stretching now, START. Do not let little things like that dissuade you from one of the "foundations" of physical fitness.

Here is how I look at it and I think most trainers and people with common sense would agree. Muscles at their optimal length are less likely to cause injury than those that are tight and imbalanced. Let me illustrate. We know that a tight psoas muscle will cause the opposing glute muscle to not fire correctly. This is called reciprocal inhibition. The glute muscle is a primary mover in actions like running. So if the glutes don't fire correctly the hamstrings must take over. Don't you think that if the prime mover is not working correctly and another muscle has to take over that injury is more likely to occur? I do.

As the psoas example illustrated an obscure relationship on how a tight muscle might indirectly lead to injury I would like to illustrate another obscure example. "Sports involving bouncing and jumping activities with a high intensity of stretch-shortening cycles (SSCs) [e.g. soccer and football] require a muscle-tendon unit that is compliant enough to store and release the high amount of elastic energy that benefits performance in such sports. If the participants of these sports have an insufficient compliant muscle-tendon unit, the demands in energy absorption and release may rapidly exceed the capacity of the muscle-tendon unit. This may lead to an increased risk for injury of this structure. Consequently, the rationale for injury prevention in these sports is to increase the compliance of the muscle-tendon unit.

Recent studies have shown that stretching programs can significantly influence the viscosity of the tendon and make it significantly more compliant, and when a sport demands SSCs of high intensity, stretching may be important for injury prevention. This conjecture is in agreement with the available scientific clinical evidence from these types of sports activities…..." ([8] Witvrouw E, 2004) Phew. I hope you made it through all that scientific jargon. It's time to wake up.

Further, there is some evidence to suggest pre-exercise stretching reduces the incidence of muscle strains. But the author mentions there is a need for more studies in this area. ([5] McHugh MP, 2010)

In summary, your goal is to create optimal length in the applicable muscles so that injury is reduced and performance increased. But, there seems to be insufficient evidence to suggest stretching does not reduce injury. You want to be careful with the studies that say stretching does not reduce injury. There are a lot of factors to consider before we say don't stretch. First, I don't know of anyone who would say that. I would venture a guess to say many of those researchers would advise to continue stretching. Second, every trainer you ask would say to stretch. Third, consider the indirect and obscure relationships mentioned previously of lack of flexibility and injury possibilities. They are real and should be enough to keep you stretching. In the end, you must stretch. I point out both sides of the argument using science and scientific reviews. You will come across more that say stretching does not decrease injury. Not for one moment should think stretching is a bad idea.

Modern Stretching Warms up the Body and improves performance

Modern stretching in my mind is far more than just a lengthening of muscles. It also prepares the body for performance by warming up the body and waking up muscles. This process is typically done through dynamic stretching.

Dynamic stretching is a key part of the warm up. The unfortunate part is some find it common for some athletes to skip their warm-up routine. This is a huge mistake. As an aside, one study showed that applying a targeted warm up routine can reduce injuries by up to 30%. ([3] Kirkendall DT, 2010) The dynamic warm up will prepare the body for the sport by waking up the body. A warm up will increase blood flow, and increase the speed of nervous impulses. ([6] Shellock FG, 1985)

Dynamic stretching can actually improve performance. In a study called "effects of static stretching for 30 seconds and dynamic stretching on leg extension power" they found that first static stretching did not improve performance. But when dynamic stretching was applied, leg extension power actually went up compared to non-stretching. ([10] Yamaguchi T I. K., 2005) This does not mean you should stop static stretching.

To further solidify my point that stretching does improve performance let me provide one more study. The purpose of this study was to clarify the acute effect of dynamic stretching on performance. To not bore you with the details, this study also showed that dynamic stretching significantly improves power output. ([9] Yamaguchi T I. K., 2007)

In a warm up routine I see static stretching putting the muscles to sleep (not literally). There is even evidence to suggest static stretching causes a decrease in strength and power. Again, this does not mean to stop static stretching.

Does stretching reduce muscle soreness?

I went through a couple studies relating to stretching and soreness reduction. One review of stretching and soreness looked at 10 studies and found that stretching does not reduce post exercise muscle soreness.

The Dos and Donts of Stretching

Ballistic stretching

Even the body during stretching must follow basic physiology principles. It is that physiology that guides how we stretch. It is also the physiology of muscles that guides how we should not stretch. The body contains muscle spindles. These are reactive to changes in length and velocity. During ballistic stretching you perform bouncing movements which might activate these spindles causing an increase in tension. It does not make sense to stretch a muscle that has activated its tension mechanism. Doesn't it make sense to stretch a relaxed muscle?

Increasing Flexibility too much

Should you continue to increase your range of motion (ROM) or is there a point that too much ROM can be bad. We'll there is a point where too much causes concern. There is evidence to suggest that increases in ROM beyond function through stretching can actually cause injury and decrease performance. ([7] SJ., 2003).

Don't stretch too far

Stretching should only happen to the point of slight discomfort. Going beyond that can cause possible injury. You can usually tell the difference between slight discomfort and pain resulting from injury. The body has a great communication system. Listen to it. If at any point you feel "injury pain" stop immediately.

Don't compete during stretching

Athletes are competitive and want to outperform their teammates. Putting them into a competitive situation with stretching can be dangerous. Each athlete should be measure by his/her own performance and improvement. Creating a competitive environment could cause an athlete to stretch too far beyond the point of slight discomfort. Remember, we are stretching to decrease injuries, not cause them.

The Old Way

In reality, the old way is still the new way of stretching for some. I believe that not enough education has happened to move youth soccer players and coaches along with current strength and conditioning trends. Because of this we have youth players performing outdated stretching and warm up routines or not doing them at all. The old way looks something like this. Trust me, you'll recognize it. Run around the field a few times followed by static stretching then game or soccer specific warm up like small sided games, shooting, etc. The new method is this in order:

1. Foam Rolling
2. Static Stretching
3. Dynamic Stretching/Warm Up
4. Sport Specific work with the ball

I understand foam rolling may be difficult to perform before a game or practice so do it when you can, especially before your own personal workouts. Foam rolling is great to do while watching TV.

How to Stretch

This is where the rubber meets the road. We've illustrated some of the fundamental concepts associated with stretching and tried to back it up with science. Now we talk about how to stretch. In the end, you will come away with a greater understanding of stretching and be able to apply stretching with yourself or team in the future.

Should you stretch cold?

I know this will cause many to pause and think is it really true. Because I like you have always been taught to warm up before stretching. You've been taught that stretching cold can cause injury or you won't get any effect from stretching cold. Analogies of stretching a frozen rubber band have caused enough fear to keep most if not all of us from stretching cold. So what is the truth?

Just recently, I've come across information that has shown it OK to stretch cold. In fact, Mike Boyle, one of the most well respected trainers has advocated it. The National Academy of Sports Medicine said this, "An Active warm-up may not be necessary before stretching when an improvement of ROM is the goal." (Range of motion) (Lucett, 2011)

As a personal aside I think this is great news for those practicing fitness of any kind. Many of us possess flexibility deficits. When trying to work on those deficits it's inconvenient to hop on a bike or go for a jog just to work flexibility. But now with this new "modern" information it appears it is OK to stretch without a warm up when ROM is the goal.

Static Stretching

What is Static Stretching?

As "static" implies it means no movement. You simply get into the stretched position where slight discomfort is felt and hold it for the prescribed time frame and relax.

Why static stretch?

Static stretching must be done the way it's prescribed or the benefit will be reduced. Stretching follows physiological guidelines. There is a reason you hold your stretch.

Autogenic Inhibition

Autogenic Inhibition protects the muscles from excessive tension. It works when the GTO overrides the effects of the muscle spindles allowing the muscles to relax. If the muscle spindle were to be allowed to fire without inhibition the muscles would tense up creating a poor environment for stretching. During static stretching it's desirable to have relaxed muscles. To get the GTO (Golgi Tendon Organ) to fire, thus relaxing the muscle, you must hold your stretch without movement for a given time.

Static Stretches practices to avoid

Rounding the back Rounding the back can be a very dangerous habit during static stretching. I think most people do it but don't realize the strain it can put on the lower back. In the stretch seen to the right the female athlete is performing a hamstring stretch. She is obviously rounding the back. It's better to do this stretch with a straight back to isolate the hamstrings.

Legs over head Commonly, athletes will perform the legs over the head stretch. Sorry I don't know what to call it. It is where the athlete has just the shoulders, neck and head on the ground with the back arched over and the legs extended over the head. If you do this stretch STOP. If you teach this stretch, STOP. If you are thinking about doing this stretch, STOP.

The Hurdler Stretch-The right way and wrong way There is a right way and a wrong way to perform the hurdler stretch. In the image to the right it's incorrect to tuck your leg. It is not the sitting up straight that makes the stretch bad, it's the pressure on the knee.

Static Stretching Guidelines

• 1-3 repetitions per muscle
• Hold each stretch for 10-30 seconds without bouncing
• Perform static stretching 3-6 times a week
• Stretch to the point of slight discomfort
• If you feel any sort of injury pain stop immediately

Exercise summary

The table below provides a summary of the appropriate exercise intensities, time and rest periods required to train the phosphagen, glycolytic (anaerobic) or oxidative (aerobic) energy systems [1].

% of Maximum Power	Primary System Stressed	Typical Exercise Time	Range of Exercise to Rest Period Ratios
90-100	Phosphagen	5-10 seconds	1:12 to 1:20
75-90	Fast Glycolysis	15-30 seconds	1:3 to 1:5
30-75	Fast Glycolysis & Oxidative	1-3 minutes	1:3 to 1:4
20-35	Oxidative	> 3 minutes	1:1 to 1:3

Aerobic Capacity

Aerobic capacity is the ability to maintain a high work output for a long period of time, while anaerobic capacity is the ability to perform very high workloads repeatedly. It is essential to train aerobic capacity as individuals with high baseline endurance are more resistant to fatigue and will have a faster recovery. This is supported by research, which found that tennis groundstroke hitting accuracy decreased by 69% from rest to volitional fatigue, while service accuracy decreased by 30% [2]. Training the anaerobic system plays an important role in improving an individuals' tolerance to lactic acid build up and therefore their ability to cope with the stop-start nature of many sports.

Meets the demands of the sport Sports such as soccer, rugby, basketball and hockey involve intermittent exercise with bouts of short, intense activity breaking up longer periods of low level, moderate intensity exercise. In soccer about 75-90% of the total body's energy expenditure and consumption come from the aerobic system [4] and although high speed actions only contribute around 11% of the total distance covered, they generally are the key moments of the game that directly contribute to goal scoring opportunities [3]. Consequently, soccer (and other games sports) uses a combination of aerobic and anaerobic metabolism, alternating between intense work and active recovery.

It is essential that interval training mimics the physical demands that are encountered during match play. There is no use sprinting for distances and durations that are not related to the sport and clearly both aerobic and anaerobic energy systems must be stressed. The following interval sessions provide a range of sprint distances, speeds and inclines, with varying periods of active recovery. Although match situations are ultimately the best way to improve sport specific fitness, these structured interval sessions can act as an effective alternative.

Example Interval Sessions

The interval sessions that I have constructed are designed for a treadmill, however they can be applied to other exercise machines or field based training. There are 8 different sessions, which look to target the aerobic system, anaerobic system or a combination of both. Sprint and recovery speeds are suggested however should be adjusted according to your ability in terms of fitness and speed capacity.

Alternatively in terms of heart rate For the glycolytic sessions, sprints should work you to 80-90% Max Heart Rate (MHR), the oxidative session sprints should work you to 75-85% MHR and the mixed session sprints should work you between 75-90% MHR

Treadmill Interval Session (glycolytic 1)

• Sprint Speed: 16-22 km/h (Fastest)
• Recovery Speed: 7-10 km/h
• Incline: 0.5%
• Sprint 60 sec - Recovery 180 sec
• Sprint 40 sec - Recovery 120 sec
• Sprint 30 sec - Recovery 90 sec
• Sprint 20 sec - Recovery 60 sec
• Sprint 10 sec - Recovery 30 sec
• Complete 4 times with 2 min rest between each block (B).

Treadmill Interval Session (oxidative 1)

• Sprint Speed: 14-20 km/h (Fast)
• Recovery Speed: 7-10 km/h
• Incline: 0.5%
• Sprint 60 sec - Recovery 60 sec
• Sprint 40 sec - Recovery 40 sec
• Sprint 30 sec - Recovery 30 sec
• Sprint 20 sec - Recovery 20 sec
• Sprint 10 sec - Recovery 10 sec
• Complete 4-6 times with 2 min rest between each block (B).

Treadmill Interval Session (glycolytic 2)

• Sprint Speed: B1 = Fastest (-1km/h each B)
• Recovery Speed: 7-10 km/h
• Incline: 1%, 2%, 3%, 4% (B1-4)
• Sprint 60 sec - Recovery 180 sec
• Sprint 40 sec - Recovery 120 sec
• Sprint 30 sec - Recovery 90 sec
• Sprint 20 sec - Recovery 60 sec
• Sprint 10 sec - Recovery 30 sec
• Complete 4 times with 2 min rest between each block (B).

Treadmill Interval Session (oxidative 2)

• Sprint Speed: B1 = Fastest (-1km/h each B)
• Recovery Speed: 7-10 km/h
• Incline: 0%, 1%, 2%, 3%, 4%, 5% (B1-6)
• Sprint 60 sec - Recovery 60 sec
• Sprint 40 sec - Recovery 40 sec
• Sprint 30 sec - Recovery 30 sec
• Sprint 20 sec - Recovery 20 sec
• Sprint 10 sec - Recovery 10 sec
• Complete 4-6 times with 2 min rest between each block (B)

Treadmill Interval Session (Mixed 1)

• Sprint Speed: Varied (14-22km/h)
• Recovery Speed: 7-10 km/h
• Incline: 0.5%
• Sprint 60 sec (medium sprint) - Recovery 180 sec
• Sprint 30 sec (fast sprint) - Recovery 90 sec
• Sprint 10 sec (fastest sprint) - Recovery 20 sec
• Sprint 30 sec (fast sprint) - Recovery 30 sec
• Sprint 60 sec (medium sprint) - Recovery 60 sec
• Complete 6 times with 2 min rest between each block (B).

Treadmill Interval Session (Mixed 2)

• Sprint Speed: Varied (-1km/h each B)
• Recovery Speed: 7-10 km/h
• Incline: : 0%, 1%, 2%, 3%, 4%, 5% (B1-6)
• Sprint 60 sec (medium sprint) - Recovery 180 sec
• Sprint 30 sec (fast sprint) - Recovery 90 sec
• Sprint 10 sec (fastest sprint) - Recovery 20 sec
• Sprint 30 sec (fast sprint) - Recovery 30 sec
• Sprint 60 sec (medium sprint) - Recovery 60 sec
• Complete 6 times with 3 min rest between each block (B).

Treadmill Interval Session (Mixed 3)

• Sprint Speed: Varied (14-22km/h)
• Recovery Speed: 7-10 km/h
• Incline: 0.5%
• Sprint 120 sec (medium sprint) - Recovery 180 sec
• Sprint 60 sec (medium sprint) - Recovery 90 sec
• Sprint 30 sec (fast sprint) - Recovery 60 sec
• Sprint 20 sec (fast sprint) - Recovery 20 sec
• Sprint 10 sec (fastest sprint) - Recovery 10 sec
• Complete 4 times with 2 min rest between each block (B).

Treadmill Interval Session (Mixed 4)

• Sprint Speed: Varied (14-22km/h)
• Recovery Speed: 7-10 km/h
• Incline: Varied (1-3%)
• Sprint 120 sec (medium sprint) 1% - Recovery 180 sec
• Sprint 60 sec (medium sprint) 2% - Recovery 90 sec
• Sprint 30 sec (fast sprint) 3% - Recovery 30 sec
• Sprint 60 sec (medium sprint) 2% - Recovery 90 sec
• Sprint 120 sec (medium sprint) 1% - Recovery 180 sec
• Complete 4 times with 2 min rest between each block (B).

All of the sessions involve active recovery, which should be a very slow jog. In sessions where the gradient increases by 1% for each block, the maximum sprint speed should decrease by 1% each time. In sessions that involve varied sprint speeds, ensure that there is at least 1km/h difference between each speed (medium, fast, and fastest), so don't start too fast!

Planning the Training

Demands of the sport

As with all team sports, playing position clearly affects the physical requirements. It is generally accepted that a goalkeeper does not need the same level of aerobic conditioning as a central midfielder. The distance covered by outfield players has been well researched. In a match, they each cover about six miles, though this obviously depends on whether you are a utility midfield player or a sweeper. There does not appear to be much difference between the distance covered by the top professionals and non-elite players.

This means that all outfield players need a reasonable level of aerobic conditioning. When aerobic power has been measured in soccer players, typical V02max values tend to be in the 50 to 60 ml/kg/min. This is a little below the value one would expect for 10K runners, who cover the same sort of distance in their competition. The reason is that a 10K runner keeps up a sustained pace at a high percentage of V02max, while a soccer player may cover the ground in a variety of ways: sprinting short distances, jogging, walking, shuffling and moving sideways and backwards. With this in mind, the training program should consist of more than steady state running, or basic interval training around a track, in an attempt to mimic the movement patterns of an actual game.

Development of speed is essential in soccer, where ability to reach the ball first, or outrun opponents, is paramount. Good soccer players will turn out 30 metre sprint times of well under 4 seconds, yet this alone is not enough. Speed endurance is vital as well, to maintain that pace throughout a match, especially during intense bursts. Agility is another important factor, since quick lateral movements may help you to feign and evade opponents. When it comes to set pieces, the tall and strong players are usually the target men. Leg strength and power are a crucial part of jumping ability. All round muscular strength is important in such a physical game, thus the musculature associated with sound posture should also be well toned to reduce the risk of injury.

Phases of Training

With a season that lasts from the end of August to May, it is difficult to be in peak condition for every match, the dream of any manager! Much conditioning training takes place in the summer months, preparing for the winter campaign. Most of the running training is done then and strengthening work carried out. In some European countries the season is split into two halves, with a break over the Christmas period. This double periodised year gives a physiological benefit and is likely to reduce the number of injuries. One current Premier League team follows this philosophy even though there is no break in our playing season; it simply goes back to endurance work midway through the winter. The problem here is that players run the risk of being over tired in matches during this period and lose speed and sharpness.

The training week

The training week is likely to be focused around the matches that are scheduled. Many professional teams have an easy day before a match, with just light skills work and travel, while the day after is usually a rest day. This does not leave much chance for physical training, especially when a manager wants to work on skills. Such work will include multiple sprints, perhaps within the penalty area, with short recovery periods before the next burst. Shuttle sprints are very popular with team managers because the sessions are easy to structure and monitor. However, an astute manager should avoid the "no pain, no gain" philosophy prevalent in the sport and choose a more appropriate workout.

Recovery runs the morning after a match can prepare players for the next batch of training and will help maintain an endurance base. These runs can last for up to an hour, provided the players are fit enough and intensity is kept at a low level. Workouts to develop speed, such as running drill sessions or resistance training exercises, need not be exhausting and are most effective when players are not heavily fatigued.

It is important to remember that small sided games, commonly used for practice, are themselves a form of physical conditioning training more specific to the demands of the sport than any strength or running workout, so they do not necessarily have to be followed by an "eyeballs-out" interval session.

How to Win the Penalty Mind Game

Watch the hips

Mark Williams, head of science and football at Liverpool John Moores University, explained: "If the taker's hips are square-on to the goalkeeper in a right-footed kicker, the penalty tends to go the right-hand side of the keeper. If his hips are more 'open', the kick tends to go the left."

His study investigated saving strategies by showing goalkeepers life-sized video footage of strikers before and during penalties. He stopped the film four times: 120 milliseconds before the kick; 40 milliseconds before; at the point of impact; and 40 milliseconds afterwards. Each time, he asked the keepers to predict the outcome.

Semi-professionals were consistently better than unskilled amateurs at guessing which of four target spots in the goal the ball would hit. At 120 milliseconds before impact, half the semi-pros guessed correctly. The success rate rose to 62 per cent 40 milliseconds before, and 82 per cent at impact. At each stage, the amateurs lagged ten percentage points behind the semi-pros.

Williams reported that other visual cues include angle of the striker's run-up and the orientation of the non-kicking foot. lan Franks and Todd Harvey at the University of British Columbia identified this latter factor as the crucial cue in a study of 138 penalties in World Cup competitions between 1982 and 1994. The non-kicking foot pointed to where the ball would go 80% of the time.

The question is, will this information make things harder for strikers, or will it introduce a new dimension to the mind game as strikers try even harder to disguise their intentions?

How to improve the function of the hamstring muscles for speed

Injuries reduced

The reality is that provided sufficient and appropriate strengthening work has been carried out in parallel with flexibility development then the biomechanics of sprinting are better supported. The potential for injury is also significantly reduced. Despite an ever-increasing body of sometimes conflicting information on when and what to stretch there still remain vague or even inaccurate guidelines on 'how to' stretch and indeed 'why'.

Planning

Identifying poor flexibility in the hamstrings is not always as easy as may be imagined since other factors may be involved including poor technique, other restrictions or a history of injury. However, once a coach or trainer knows the athlete they are working with then consistency in performance can usually be established and any limiting factors clearly identified such as short stride length. Consultation with a qualified Physiotherapist at this stage is always a good step to confirm beliefs and to help bring out any history of injury in this area. Stretching should follow the principle of regular controlled progressive static stretching of fully warmed-up muscle in sessions largely run separately to other training sessions along with the integration of suitable dynamic stretching activities as part of normal session warm-up.

Assessment

Use of the classical 'sit and reach test' can help to establish current hamstring flexibility and be used to set a target for improvement within an agreed time.

Exercises - static stretching

There are many examples in the literature of hamstring stretches. However, many of these cases fail to take account of modern best practice (how long, how often, when etc), contra-indications (opposite knee under pressure in 'hurdles' position or arching of the spine, for example) and specificity (what is actually being stretched). The best single, most effective, safe and specific hamstring group stretch from personal experience and the advice of Physiotherapists is the seated, bent leg stretch as shown in figure 1.

Relaxed

Extended

Figure 1 - The seated bent knee hamstring stretch

How to start

Sit comfortably on a bench or similar support that allows the foot of the free leg to rest comfortably on the ground. Position a suitable support - e.g. cushion under the knee of the leg to be worked to ensure a partially flexed knee is maintained. Sit 'tall' with hips neutral and move the whole upper body forward toward the leg keeping alignment throughout - there is simply no need to stretch out with the arms or to grasp the shin for example - often this just leads to poor posture and an ineffective stretch! Hold the stretch for 10 seconds and repeat 3 times. Work both legs in turn.

Progression

Extend the hold time to 20-30 seconds. Increase the number of repetitions in a session up to 10. Increase the frequency of stretching to several times per week. Use the 'sit and reach test' to determine improvement. Re-assess every 6 weeks or so.

This stretch has a number of advantages including - a comfortable position, there is no unnecessary strain elsewhere in the body, specificity - it stretches the hamstring muscle.

NOTE: performing a hamstring stretch with a straight leg is generally not recommended for specifically increasing hamstring muscle flexibility - with the leg straightened the tendency is for the stretch to be taken up by the muscle tendons - try it for yourself and see if you can feel the difference - I guarantee that in 9 out of 10 cases you will feel the stretch in the back of the knee with a straight knee and in the 'belly' of the hamstring with a bent knee.

Maybe the prevalence of guidelines to stretch with a straight knee also underlies the relatively high injury rate?

Exercises - dynamic stretching

Progression to a specific dynamic stretching activity can reap great rewards. Using the standing dynamic 'leg cycling' drill is great for developing coordination, rapid contraction and relaxation through an extended range (flexibility) and for developing specific hamstring strength / power (figure 2). Recent research has highlighted the fact that in sprinting the biceps femoris muscle is the last of the group of three hamstring muscles to 'fire' during the sprint cycle and is often left exposed at the end of the support phase leading to injury if there are limitations in flexibility, strength and coordination present.

Start

Drive Down

Recovery

Figure 2 - Phases of the leg cycling drill

How to start

A good start is to work on 3 sets of 10 cycles at around 1 cycle every 2 seconds, slowly lifting the knee so that the upper leg is presented parallel to the ground and then driving the leg back and downwards in a rapid controlled movement with the foot kept fully flexed at the ankle (dorsiflexed). The ball of the foot should be allowed to just contact the ground (note: spikes should not be worn for this exercise!). To best match the specifics of movement in sprinting the leg should be actively 'recovered' as soon as the foot touches the ground and is directly below the body i.e. it should not be allowed to swing out of control behind the body - this takes practice! Work both legs evenly unless seeking to address an imbalance!

Progression

This activity can be made progressive in terms of the cycling rate (up 3 per second), the duration (up to 15 seconds), the range of movement (particularly knee lift and height of foot recovery or knee flexion) and the focus within the cycle (developing to a smooth complete cycling action).

Summary

Combining controlled, static stretching with a suitable progressive dynamic workout can improve sprinting performance, dramatically reduce the chance of hamstring injury and can be used extensively in rehabilitation following muscle injury.

Interval Training

VO2 max

If you are a soccer player, you may already perform high-intensity shuttles separated by short recoveries to improve your speed endurance. This may also have the added benefit of boosting your aerobic system, because volumes of research have shown that the best way to lift your VO2max (an index of aerobic fitness) is to train at an intensity close to, or above, VO2max. Realistically, this work has to be done in an interval format if the session is going to last any serious length of time-otherwise, after one hard burst for a few minutes you may end up collapsed in a heap of fatigue. This is where the true benefits of interval training become clear: by separating your efforts with short bouts of recovery, you can keep the intensity high, yet extend the volume.

Plan the session first

Our soccer player, however, may be guilty of the cardinal sin of all training: not thinking about and planning the session sensibly beforehand. The very nature of the session working at high intensity leads to the belief that the athlete should be thoroughly exhausted at the end. Yet it is the route to that exhaustion that is often ill-considered how to make the session more than simply running flat out for as long as possible and then going again on command. The coach should have a clear idea of the physical demands of the sport concerned, particularly the metabolic demands with regard to which energy systems are utilised during the performance. Video analysis of a match can determine typical activity patterns for games players, or heart rates and lactates can be monitored in a race. Armed with such information, you can make sure that the session you are considering is geared to the demands of your sport. Most coaches can gather this information from books and articles about their sport, but measurements on individuals can also help to build up the picture.

Getting the recovery time right

With the demands of the sport in mind, the coach should carefully consider each of three key aspects of the session: intensity, duration and recovery. Each of these can combine to govern which energy system is utilised to provide the bulk of energy in the muscles used during the mechanical work. If, for example, our soccer player wishes to improve his speed off the mark, he should choose a session with short but explosive activity such as 30m sprints at maximal speed. Here intensity is the key factor, so High Energy Phosphates (HEP) will be the immediate major source of the ATP (Adenosine Triphosphate) needed to fuel such activity. In such short intensive work, the recovery should be long enough to allow repletion of the HEPs, because if the recovery is too short an alternative energy system will have to be recruited and the quality of the session will be impaired.

Judging the exact recovery time to perfection is not always easy. Research has shown that the repletion of HEPs, after a sprint, starts very quickly and then slows. It takes about 20 seconds for the HEP stores to get back to half of their resting level, but a further 170 seconds to be topped up to normal. Therefore, if our player wants to keep the quality high, the recovery period should be about three minutes. In winter this may mean putting on and taking off clothing in between the short reps.

Sprinting quickly is only one aspect of soccer, and there may need to be a session dedicated to the ability to repeat high-quality sprints in rapid succession. This will require a different type of interval session because the player is working on the recovery aspect. Here he should cut the recovery between bursts so that the work is repeated before the HEPs are fully back to resting levels. Such activity requires a greater contribution from glycolysis, a different energy pathway that breaks carbohydrate down, producing ATP very quickly. A series of such sessions may well improve not only lactate tolerance but also the time required to replenish the HEP stores, both of which should enhance soccer fitness.

The type of recovery between efforts is also of paramount importance. Simply standing around with hands on hips, or bent double, is far less effective than walking or, better still, jogging. This active recovery actually helps to remove and disperse lactate that accumulates in the working muscles during intensive exercise. Indeed, active recovery can almost halve the time that is taken for muscle and blood lactate to return to resting levels after an intensive burst, and is likely to be even more effective in the aerobically training athlete.

Fartlek for games players

Another type of session can work on both of these aspects as well as on the oxidative system. Although not a structured interval session split into reps and sets like those already described, "fartlek", mixing fast with slow work, can be of immense benefit to those who play field sports. Fartlek comes from the Swedish for "speed play" and has been used by distance runners for years. But for games players, the session should not just use running, but also jogging and walking to fit in with the demands of the sport. After all, no soccer player actually runs for the whole 90 minutes of a match-the pace is varied. Similarly, the direction of work should not always be straight ahead. This may be important for the track runner who has to cover the ground as quickly as possible in one direction, but the games player has to go forwards, backwards and from side to side.

This must all be taken into account if the training session is going to mimic accurately the pattern experienced in a match. Remember, if you are a games player, you are not training to be a better sprinter, you are training to be better at your game. Therefore, sprinting should not just take the form of back and forth shuttles but should make you change direction or even imitate a slalom. This is where the imaginative element comes into play.

Progression is another aspect you need to consider. If you are to improve your condition, there should always be some element of progression in your schedule. With interval training, you have plenty of options to work with. For instance, you can lengthen the distance of your efforts. This is fine if you are a runner, a rower or a cyclist because you can build up the distance closer to your actual race distance. For the games player, or sprinter, however, this may not be so appropriate. In field sports, it is rare to have to sprint more than 30m in one go, so it is questionable whether long sprints are a suitable focus in training.

You can improve the intensity, which usually involves performing your reps a little faster. Here you must be careful to keep things specific, because if you are, say, a 10K runner it may not be appropriate to be running reps too fast in training. For example, you may be performing aerobic intervals, where the idea of the session is to give optimal stimulus to the aerobic system. The session might be 5 x 1 mile, where the intention is to be working at your maximum aerobic steady state. You can use heart rate in such sessions to control the intensity and make sure that you are not going too fast

However, if you are performing quicker, shorter repetitions on the track, heart rate may not be the best guide. In such super-maximal intensities, the heart rate does not quite reflect the high intensity encountered, partly because the reps are too short and the heart rate needs time to reach a steady state. Here it may be more appropriate to use split times to set your goals, with a gradual reduction from session to session to ensure an element of progression.

To improve your endurance, you can cut the recovery time allowed between reps. You can do this systematically - for example, by cutting the recovery time by five seconds each week. If you use a set recovery period, your heart rate before each rep will rise throughout the session. Alternatively, you can use your heart rate to determine your recovery. If you want to maintain quality in a session of 3 x 800m, rather than use a specific time for recovery, you can try waiting for the heart rate to drop to a specific level such as 120 or 100. As individuals vary so enormously in both their resting and maximum heart rates, it is impossible to give a general figure for everyone to aim for, but trial and error should produce a rate that works best for you.

Another way to build endurance is to add to the volume of your session. You can increase the number of reps performed in various sets during the session or even build on the number of sets performed. As long as this is part a structured plan and conforms to the demands of your sport, it should work well, being a tried and tested method for improving fitness in most sports.

Finally, if you intend to start interval training or rethink your schedule, remember:

1. Think about the aims of the session first, before you go to exhaustion
2. Make sure the session is specific to the demands of your sport in terms of intensity, duration and volume
3. Consider carefully the mode and length of recovery
4. Keep the movement patterns similar to those used in your sport-you don't always have to run
5. Make sure there is progression from session to session, but avoid improving more than one aspect at a time
6. Be imaginative in building your sessions - you don't always have to use sets of 10

Kicking Accuracy

Measuring accuracy

Frustrated by the limitations of existing methods for assessing kicking accuracy - clearly a vital component of football performance - a research team from Minnesota in the US set out to develop and test a sensitive, reliable and valid means of measuring kicking accuracy that was relatively inexpensive, simple to make and easy to use.[Journal of Science and Medicine in Sport 5(4):348-353]

The result of their endeavours was a plywood target 243.5cm wide and 122cm high, held in an upright position from behind by a wood plank frame. The surface of the plywood was covered with a textured white paint; while a black mark measuring 5cm squared (the bull's-eye) was placed at the midpoint of the base of the board. A screw was placed in the middle of the bull's-eye in such a way that a hook at the end of a tape measure could fit over the head of the screw with a view to precisely measuring the distance from the bull's-eye to the centre of the mark left where the ball struck the target.

Sheets of white paper covered by carbon paper were placed over the board, such that when the football struck it left a mark on the underlying white paper. For each new kick, a new sheet of paper-plus-carbon was used.

To test the accuracy of the system, 10 ball marks were created on the target by having a subject kick a football at it 10 times from a distance of 6.1m. Two 'raters' then independently measured the distance from the bull's-eye to the centre of each ball mark, each taking the marks in a different random order. They then repeated their measurement on the same day, taking the marks in a different random order.

Analysis of the results showed a high degree of inter- and intra-rater reliability in measurement, with distances from the bull's-eye to the ball mark (ranging from 25.7cm to 150.75cm) accurate to within 0.15cm. These results suggest that our method for assessing kicking accuracy is a useful, valid and reliable tool for analysing performance in soccer players,' state the researchers. To our knowledge, no other tool has demonstrated reliability. Measurements were made to within 0.15cm, suggesting that the target is sensitive to change in kicking accuracy. Such targets may also be useful in sports other than soccer, such as lacrosse, ice hockey, field hockey and ...handball.'

This particular device was tested indoors in a gym. But the researchers point out that game situations could be simulated more accurately by using defenders or a goalie against the player kicking at the target, placing it on a playing field - although not in rain or extreme wind - and/or making it larger to replicate the size of an actual goal (244x732.5cm).

Training and research are the two main applications of the target, they conclude. The bull's-eye could be moved to different places on the target, allowing players to practice kicking to specific spots. Each player's accuracy could be determined for each spot, and regions to which the player does not kick accurately could become a primary focus of training. The target could then be used to measure improvements in accuracy over time.

Nutritional Advice

The Keeper

The specific demands of the different positions within a team are not as clearly defined as in some other team sports, such as rugby union. The obvious exception to this is, of course, the goalkeeper. A keeper relies little on the aerobic system for energy production since all the important phases of play for him last a relatively short time. The key performance quality of the keeper is probably agility, and this can be broken down further to include speed, power, strength and flexibility. If he happens to be tall, it's clearly an added bonus!

Popular training programs for keepers include repetitions of short sprints performed at maximal speed, with many changes of direction involved. Obviously, an element of skill can be built into this training by having to save a bombardment of shots at goal. This way, another important constituent of training is then automatically introduced, namely, the ability to regain one's feet in order to save a follow-up shot at goal.

However, to gain the edge in physical development, the keeper should also train away from the pitch so that upper and lower body strength and power can be improved in the weights room. In addition, plyometric training lends itself perfectly to improving the qualities necessary for agility around the goalmouth. Plyometric training does need to be conducted correctly, which includes the provision of generous rest periods between sets of exercises, but if done so can produce some significant improvements in the ability to move one's own body weight at speed.

Outfield Players

As far as the rest of a soccer team goes, the differing demands are less obvious. However, a systematic analysis of soccer matches on video has shown that midfield players tend to cover the most distance, and other studies have - not surprisingly - shown these players to have the highest VO2max scores, and to show the least fatigue when performing many repeated sprints in succession. Compared to forwards and defenders, midfield players tend to have a more continuous involvement in the game. However, while forwards and defenders usually have more time to recover between sprints, they also need to perform those sprints at a faster speed to be successful in their crucial phases of play.

Implications for training should become apparent. Clearly, the midfield players need more of an all-round fitness profile, with an emphasis on both aerobic and anaerobic capacity. Aerobic capacity relates to sustained performance (20-40 minutes), or performance during lengthy repetitions, each of 2-3 minutes in duration. Anaerobic capacity can be related to performance of a repeated nature, but with work/rest intervals of equal length, and not over 30 seconds.

The players regularly involved in attacking/ defending situations will need more training emphasis on speed. Speed training can itself be broken down into at least two phases - an acceleration component and a maximal speed component. For improvements in acceleration, repeated sprints of not less than six seconds in duration, performed from a standing or walking start, will be useful in training. This will help develop the neuromuscular function of the athletes. For development of maximal speed, a gentle increase in speed to about 85 per cent followed by a sustained burst at maximum speed for about six seconds will produce improvements that are more specific. This will help develop both the metabolic and neuromuscular qualities of the muscles involved. Put simply, to improve acceleration, accelerate as fast as possible in training. To improve maximal speed, the length of time spent running at current maximal speed during training should be increased. A relatively gentle acceleration phase before a sustained burst can best achieve this.

If the coach can accomplish these sorts of training goals by using drills that involve ball skills, then the players will become used to performing the skills under conditions of fatigue. As many will appreciate, it is under conditions of fatigue and mental pressure such as a competitive match that skills often become lost - unless they are both well-drilled for their own sake and practiced under simulated conditions of fatigue.

Match-play

Moving away from training methods for a moment but continuing the analysis of the physical demands of the game, there is an interesting form of player behaviour that playing experience seems to encourage. Many players will recognise a phenomenon as common without perhaps understanding why. The behaviour in question is the avoidance of prolonged high-intensity activity that would require a corresponding long period of recovery - which can rarely be afforded in a competitive situation.

For instance, if a defender is involved in high-intensity activity as he assists in an attacking phase of play, he often will not attempt to return to his defending position in time for the immediate counter-attack. While this might be perceived as laziness, it may benefit both the individual player and the team in the longer term, providing the rest of the team has sufficient cover to deal with the counter-attack.

Sound physiological reasoning provides the basis for this. It has been shown that short periods of intense exercise (e.g. less than 15 seconds), when interspersed with rest periods of similar duration, produce a fairly low build-up of lactic acid in the muscles (a strong indicator of fatigue) even when this activity pattern is continued for some time. However, periods of intense exercise of about 30 seconds or more, even when accompanied by equal rest periods of 30 seconds (such that the work:rest ratio is till 1:1 as in the previous example), produce a far higher concentration of lactic acid in the muscles and also greater fatigue.

This situation is exactly what the experienced player is trying to avoid when he decides to return more slowly to his main position on the pitch. However, this obviously requires a large degree of teamwork, with team-mates prepared to cover for the defender concerned. If a team can achieve this sort of cooperation, it helps reduce player fatigue and increases performance capacity throughout the match as a whole. Clearly the role of the coach is paramount in organising this sort of team approach in spreading the workload, especially with inexperienced players. Indeed, some younger players may be almost too enthusiastic for the good of their own and the team's subsequent performance.

Nutrition

As already mentioned, the physical demands of the game are sufficiently high to require a high rate of energy production. Whatever the sport, this can only be done by the breakdown of carbohydrates, and soccer is no exception. This means that players should pay particular attention to this aspect of their diet - more especially when considering the notorious practices of soccer players when they are given no guidance about what to eat. The heavy training/match schedule that the British game involves only serves to increase the need for carbohydrate intake.

When discussing this subject, it is usual to express the form of the energy consumed as percentages (proportions) eaten as carbohydrate, fat and protein. While the typical diet for the general British population is about 40% carbohydrate, 45% fat and 15% protein, the recommended dietary proportions for a soccer player would be roughly 65% carbohydrate, 20% fat and 15% protein. However, the typical diet of the soccer player is actually very similar to that of the general population - too little carbohydrate and too much fat.

The work carried out some years ago by Jacobs and colleagues ("Muscle glycogen and diet in elite soccer players", European Journal of Applied Physiology, 1982, vol. 48, pp297-302) illustrates the potential pitfalls of a low-carbohydrate diet. These researchers studied players in the Malmo soccer team in Sweden -the side had finished as runners-up in the European Cup the previous season. The players consumed just 47 per cent of dietary energy as carbohydrates - well below the recommended values. Muscle glycogen stores were assessed immediately after a national league match (Day 1), and again 24 hours later after no training (Day 2), and 48 hours after the match after a very light training session (Day 3).

Muscle glycogen stores of the general population are approximately 70-90 mmol.kg-1 wet weight. The average values for the Malmo team were 46,69 and 73 mmol.kg-1 wet weight on the three days.

There is no reason why the players could not have refilled their muscle glycogen stores to pre-match levels within 24 hours if they had consumed a high-carbohydrate diet. Experiments have shown that, for highly trained athletes, a muscle glycogen level of well over 100 mmol.kg-1 wet weight is quite possible to achieve following two or three days of light training. The reason the soccer players didn't reach this sort of level was undoubtedly due to the lack of carbohydrate in their diet.

The importance of high muscle glycogen stores for performance in events lasting longer than 60 minutes has been demonstrated by numerous researchers. Specifically in relation to soccer, the diets (and hence the muscle glycogen stores) of players involved in an exhibition match have been manipulated, with those players having higher muscle glycogen stores before the match also covering a greater distance at a faster pace during the match. This effect was particularly noticeable towards the end of the match when glycogen always becomes lowered - and many goals are often scored as the game tends to open up. Therefore, a high-carbohydrate diet leads to increased muscle glycogen stores, which in turn leads to a greater distance covered during the final stages of the match, which in turn leads to your team scoring the winning goal in injury time! Well, not always, maybe, but you can increase the chances of it happening by taking a close look at players' diets.

Strength

Core strength

Most runners focus on the core area at least to a small extent in their training by carrying out conventional abdominal and low back exercises such as crunches and back extensions. However, during the running motion, the amount of active trunk flexion (carried out by the abdominal muscles) is rather negligible, as is the extent of trunk extension (a function of the low back muscles and gluteals). Compared with direct flexion and extension, there is much more rotational action in the trunk during running, yet most runners totally ignore workouts which would improve the rotational strength of their core muscles. Medicine ball training, however, can give you additional specific strength, which can be used directly during your workouts and races to improve your running velocity and overall power. The following group of exercises can provide runners competing at all distances with considerably improved core strength. Typical training weights for medicine balls range from two to 15 pounds. Larger balls (up to 25 pounds or so) are used by certain strength athletes (weightlifters, football players, bodybuilders) but are unnecessary for runners. In fact, most runners will do very well with a set of three balls which weigh about two, four, and six pounds (approximately one, two, and three kilograms, respectively).

The exercises

1. The standing trunk twist (hammer twist)

Muscle groups emphasised: Hip and leg muscles, abdominal and oblique muscles and spinal erectors.

Value for runners: This exercise develops dynamic stability strength for all of the core muscles in a standing posture, making the exercise more specific to running than many of the conventional abdominal and low back exercises that are performed in a seated position. Strong core muscles provide for an upright and economical running posture, as well as a strong anchor point for the propulsive muscles in the legs.

Weight of ball: Two pounds for beginners, four to six pounds for advanced athletes.

Other equipment: A towel.

Instructions: Place your towel flat on the ground and then put the medicine ball in the centre of the towel. Bring the ends of the towel, one at a time, over the top of the ball to create a 'ball in a sack' effect. Start the exercise with your feet shoulder-width apart and your weight shifted on to your right foot. Twist your body to the right with your hands grasping the ends of the towel and the ball positioned behind your right shoulder. While keeping your arms straight, swing the ball out away from your body towards the front and then to the left in a wide arc, while bending your legs and 'sitting' into a shallow squat position as the ball reaches the middle of the arc in front of you. Continue this arc until you finish the swing with the weight shifted onto your left foot, with your hands still grasping the ends of the towel and the ball now behind your left shoulder. Immediately swing the ball back to the starting position, and repeat the swinging motion back and forth for a total of 10 to 15 repetitions on each side. Begin this exercise in a slow manner and progress in speed (while still maintaining good control) over a period of several weeks. Perform two to three sets total.

2. Hanging body flex

Muscle groups emphasised: Abdominal, oblique and hip flexor muscles.

Value for runners: This exercise strengthens the integrative action of the muscles, which raise the thighs and stabilise the pelvis. This provides for a powerful knee drive and an economical running posture.

Weight of ball: Two pounds for beginners, four to six pounds for advanced athletes.

Other equipment: A horizontal/chin-up bar.

Instructions: Start from a hanging position with your arms overhead and your legs extended straight down towards the floor. The medicine ball should be placed between your feet and held there firmly by squeezing the feet and legs together. Raise your knees towards your chest (with knees bent) while maintaining a firm grip on the ball with your feet and ankles. Flex your toes and feet up towards your knees throughout the entire movement. Return to the starting position by extending your legs back down towards the ground under control. Perform the movement at a slow speed during the first few sessions and progress to a moderate speed over time. Use 10 to 15 repetitions and two to three sets per workout.

3. Walking trunk twist

Muscle groups emphasised: Hip and leg muscles, abdominals, obliques and spinal erectors.

Value for runners: This exercise develops stability of the core muscles, much like the hammer twist (exercise 1), but the walking twist also incorporates the integrated muscular action required during rhythmic movement. As the right leg moves forward, the trunk twists to the right, following the same oppositional pattern found in running (right leg forward, left arm forward). The added momentum gained by swinging the ball creates increased tension in the stabilising core muscles, thus strengthening them.

Weight of ball: Two pounds for beginners, four to six pounds for advanced athletes.

Other equipment: A towel.

Instructions: Start from a standing position with your feet parallel and the ball secured firmly within the towel and held up behind your right shoulder. Step forward with your left leg and simultaneously swing your arms through a wide arc in front of you. Continue the swing until your arms are shifted to the left and the ball has stopped behind your left shoulder. Continue the exercise by stepping forward with your right leg while simultaneously swinging the ball back behind your right shoulder. The swings should be fairly slow as you learn the exercise but will progress to a moderate (but controlled) speed over time. Repeat the action (stepping and swinging) for a total of 10 to 20 repetitions (five to 10 swings on each side) before resting for a few moments. Repeat for a total of two to three sets.

4. Jump and pick up

Muscle groups emphasised: The hip and leg muscles.

Value for runners: This exercise activates both the extensors and flexors of the hip during the jumping phase of the drill and thus improves explosive leg power for both the push-off and leg swing or knee-drive portions of the running stride.

Weight of ball: Two pounds for beginners, four to six pounds for advanced athletes.

Training note: To lessen the chance of injury, perform this drill on a resilient surface such as a wood floor, synthetic track, or grass.

Instructions: Start with your feet flat on the ground and the ball held firmly between your ankles. Your knees should be bent slightly so that you are in a shallow squatting position. From this position, perform an explosive jump upward and lift the ball in front of you by pulling both knees up quickly towards your chest to near chest level. Catch the ball with both hands in front of your chest as your feet land on the ground. Squat down and place the ball between your ankles before repeating the action for a total of six to 10 repetitions. Perform two to three sets.

5. Knee throw and lunge

Muscle groups emphasised: Hip flexors and quadriceps are utilised for the throwing action, quadriceps, gluteals, and hamstrings are used for the lunge, and core stabilisers are involved in both the throw and the lunge.

Value for runners: This exercise develops explosive knee lift, eccentric leg strength and coordination. The knee drive action is followed immediately by an energy-absorbing landing in the lunge position. This combination of throwing and lunging requires both strength and coordination to complete.

Weight of ball: Two pounds for beginners, four to six pounds for advanced athletes.

Instructions: Start in a standing position with your left foot forward and your right foot two to three feet back (standing start position). Your left arm will hang relaxed at your side while your right hand supports the medicine ball on the front upper third of your right thigh. The knee throw takes place as you step forward with your right foot and drive your right knee forward and explosively upward. Essentially, you are releasing the ball with your right hand and 'throwing' the ball forward with your knee. Your motion continues forward until your right foot lands on the ground in front of you, leaving you in a wide lunge position with your trunk held upright. A wall or partner can return the ball to you. Perform 10 to 15 repetitions with the right leg before switching over to the left. Perform two sets with each leg.

6. Squat, throw, fall and chase

Muscle groups emphasised: Leg muscles, abdominals, spinal erectors and shoulders are utilised for the squat and throw actions. Leg, abdominal, chest and shoulder muscles are stressed during the fall and chase movements.

Value for runners: This drill is the most dynamic of the six exercises. The squat and throw actions develop overall power in the muscles of the hips, legs, back and shoulders, muscles which contribute to a strong push off and proper posture during running. The fall action improves coordination and whole body control, as well as upper torso, abdominal and leg strength. Although some runners may laugh at the idea of practising falling, knowing how to fall can prevent injuries during workouts and races. Most runners will fall at some point in their careers, and for runners in more northerly areas, where ice and snow cover the roads during the winter, slipping and falling is rather commonplace. Also, it is important to be able to recover from falls in race situations (remember Mary Slaney's unfortunate tangle with Zola Budd and subsequent tumble during the 1984 Olympic Games?). The chase part of the exercise teaches you to get back on your feet as quickly as possible after a spill and develops strength and coordination in the shoulders, chest, abdominal area, back, hips and legs.

Weight of ball: Four pounds for beginners, six pounds for advanced athletes.

Training note: Perform this drill on grass or other soft surface to minimise impact forces. Allow yourself at least 15 to 20m of space to sprint forward during the chase action.

Instructions: Start by performing a shallow squat with the medicine ball held in front of you at chest level. Explode forward by extending both legs and arms and pushing (throwing) the ball out in front of you at approximately a 45-degree angle. Continue falling forward and catch yourself by driving one knee forward, landing with your body weight on your lead knee, foot and both hands. Rise as quickly as possible and sprint forward until you catch up with the rolling ball. Strive to keep your momentum moving forward throughout each phase of the exercise, never coming to a complete stop at any time. Walk back to the starting point with the ball and repeat the overall exercise for five to 10 repetitions. Perform two sets per workout.

General training guidelines for medicine ball workouts

Medicine ball exercises represent a form of strength training and are typically performed with other strength exercises, when you are relatively fresh and non-fatigued. Perform all twisting and lifting exercises slowly and deliberately while you are learning the movements. After a few training sessions, the actions may then be speeded up to a moderate speed, but remember to maintain good control at all times. Focus on developing good form while using light balls early on; progress to heavier balls after three to four weeks. Core strengthening exercises can actually be carried out frequently (four to six times per week) for relatively brief periods (10 to 15 minutes). The sample programme given below is a guide for including core exercises in your overall training programme (many other programs are possible).

Core exercise sample programme

• Monday: Medicine ball exercises 1 and 2 (after a tempo workout)
• Tuesday: Traditional core exercises such as abdominal crunches, back extensions, etc. (after your usual weight-training routine)
• Wednesday: Medicine ball exercises 5 and 6 (after your speed work)
• Thursday: Break day - no core training
• Friday: Traditional core exercises (after long, moderate exertion)
• Saturday: Medicine ball exercises 3 and 4 (after weight training)
• Sunday: Rest day - no core training

And sprint times, too

Another piece of research - by Taiana and colleagues in France - showed that a 10-week leg-strength training program for footballers improved their 10m and 30m sprint times and their vertical jump performance.

These motor tasks are obviously very valuable. However, this study used a training program that targeted maximum strength with heavy resistances. Although this type of training is a proven method for enhancing sprint speed and jumping power, it is also difficult to include in the regular training program of a football team, because the recovery required after heavy resistance training might interfere with the regular competitions during the season.

As with strength training the value of good sprinting speed for footballers is well supported by research. Ekblom found that the absolute maximum speed shown during play was one of the parameters that differentiated elite players from those of lesser standard. This is supported by a study with German division-one players by Kollath and Quade. They showed that professionals were significantly quicker than amateurs over 10m, 20m and 30m. The acceleration difference to 10m was especially significant. This suggests that better players need superior acceleration and maximum speed to play at a higher level. Interestingly, the 30m speed was similar for the German professionals regardless of position.

The training regimes of footballers must therefore reflect this need for good acceleration and maximum speed. Peter Apor suggests, in making fitness recommendations for footballers; that players need to develop the musculature of a sprinter. I have already mentioned the benefit of maximum leg-strength training with heavy resistances for developing acceleration and speed. Taiana says that the players he trained for maximum leg strength were able to play at the weekend without detriment if the strength workout was on Tuesday. This once-a-week routine was still found to be beneficial. However, this type of training should be used with caution. Two or three sessions a week during the off-season would bring about much greater gains in maximum strength. Taiana therefore recommends that this type of training should be used in the off-season and then maintained with one workout per week once the competitive season has started.

Step by step

Another point to remember is that maximum strength training should be a progression from general strength training with submaximal loads. Heavy maximal resistance exercise, while very effective, is for advanced strength trainees only. Zatsiorsky recommends that good abdominal and lower back strength are essential if heavy lifting exercises are to be used. Thus, the first step for improved sprint speed is ensuring a good basic level of strength. American trainers George Dintiman and Robert Ward recommend that an athlete should be able to perform one maximum leg press of at least 2.5 times body weight, and have a hamstring to quadriceps ratio of least 75-80%. Both these measures can be tested on the standard gym machines. Good abdominal and lower back strength are also essential for sprinting speed, as the trunk muscles are required to stabilise the sprinting movement.

Hop, bound and jump

Plyometric exercises are another proven training method that enhances leg power and sprinting speed. McNaughton cites soccer as one of the many games where short, explosive power is required, and that plyometric training is a useful complement or alternative to strength training to achieve this. Once the players are used to it, plyometrics may be more convenient than weights for speed development in terms of scheduling during the season.

Plyometric exercises are typified by hopping, bounding and jumping movements. These exercises demand a high force of contraction in response to a rapid loading of lengthening muscles. For this reason, they should be more accurately called reversible action or rebound exercises. The training effort increases the force production in the muscles, but the movements are performed at faster speeds than weight-training exercises. Thus rebound exercises are more specific to the sprinting and jumping movements in football. These exercises should be done in 3-5 sets of 8 repetitions for each leg, with at least one minute's rest between sets. The quality and speed of the movement is the priority. The other training element that is required for improving sprinting speed is sprinting itself. This should be done with maximum efforts over 30-60m. Again, at least one minute's rest between runs should be allowed so that quality can be maintained. Remember, with this kind of training the aim is to develop the maximum speed; endurance should not become a factor. Sprinting done uphill, with weighted jackets, or towing weights is also useful because it adds resistance to the sprint movement, placing greater load on the muscles in the most specific manner. Again, short distances with long rests are recommended.

Fitting it in I have discussed research that shows the importance of strength and speed for elite football performance. From this, I have suggested four types of training:

1. General strength training to help prevent injuries, improve kicking performance and provide the basis for good sprinting speed
2. Maximal leg-strength training, which is a progression from general strength training for advanced trainees only, but one that is extremely useful for developing speed and power
3. Plyometric training exercises, which complement strength training as an effective alternative
4. Maximum sprint running over short distances with or without added resistances

The main question that now needs answering is how can this training best be scheduled into an already full training and competing program?

Plyometrics and sprint training are usually performed when fresh. However, as it is a requirement of football to be able to sprint when fatigued, one could argue that sprint work should be done after a training session. One answer could be a short but high-quality hopping, jumping and sprints workout after a skills session. For example, 3x8 squat jumps, 3x8 skips for height, 3x8 hops for distance each leg, 3 x 30m towing runs and 5 x 40m sprints would be a short but useful workout if performed once or twice a week throughout the season. Scheduling strength-training workouts is more difficult. If the program is weekend matches only, then players could do a general strength-training workout on a Monday and Wednesday afternoon, leaving plenty of time to recover for the weekend match. However, if there are midweek fixtures, then strength training may have to be sacrificed or reduced to light workouts purely to maintain strength .

The best way for a player to develop his strength would be to start a strength-training program in the off-season. Three strength workouts a week would result in improvements.

Once the pre-season training starts, the player can reduce to twice weekly and then fit in workouts when possible during the season. This way the player can maintain the strength gains made during the summer.

Maximum strength exercises should only be targeted during the off-season. Afterwards, they should be done only once a week to maintain strength during the season. Maximum strength can only be achieved if it is concentrated on, and training for it can interfere with other important activities.

With careful planning and careful selection of exercises, keeping sessions short but high quality, extra training should be practicable, although sensitivity to the training status of the players is important when prescribing extra sessions.

The problems with developing strong hip flexors

Despite their importance to a wide range of athletic and sporting activities, the hip flexors are the most neglected major muscle group in strength training. It is very rare to find training programs that include hip flexor exercises. By contrast there is usually a great deal of emphasis on exercises for the leg extensors.

There are some obvious reasons for this comparative neglect.

The principal muscles involved in hip flexion are the psoas and the iliacus, collectively known as the iliopsoas. Because they are relatively deep-seated rather than surface muscles they may have been overlooked by bodybuilders who have traditionally been the major innovators in strength training. Secondly, there are no obvious ways to adequately exercise them with free weights. Finally, these muscles do not have the obvious functional importance of their extensor counterparts. Yet, as antagonists, both hip and knee flexors perform a vital role in controlling the rate of descent and ascent in leg extension exercises such as the squat.

There is no corresponding problem of underdevelopment with the muscles responsible for knee joint flexion, the hamstring group. Because they cross two joints they are active in both leg extension and leg flexion. They act to flex the knee joint and also to extend the hip joint. Therefore they tend to be strengthened by complex leg extension exercises. Also hamstrings can be developed and strengthened through the use of the leg curl apparatus.

The benefits

Strong hip flexors provide an advantage in a wide range of sports and athletic activities. In sprinting high knee lift is associated with increased stride length and therefore considerable attention is given to exercising the hip flexors. However, they are usually not exercised against resistance and consequently there is unlikely to be any appreciable strength increase.

Hip flexor strength is directly relevant to a range of activities in football. Kicking a ball is a complex coordinated action involving simultaneous knee extension and hip flexion, so developing a more powerful kick requires exercises applicable to these muscle groups. Strong hip flexors can also be very advantageous in the tackle situation in American football and both rugby union and rugby league where a player is attempting to take further steps forward with an opposing player clinging to his legs.

In addition those players in American football and rugby who have massively developed quadriceps and gluteus muscles are often unable to generate rapid knee lift and hence tend to shuffle around the field. Having stronger flexors would significantly improve their mobility. It is commonly asserted that marked strength disparity between hip extensors and hip flexors may be a contributing factor in hamstring injuries in footballers.

It is interesting to speculate on whether hip extensor/flexor imbalance might also be associated with the relatively high incidence of groin injuries. Other sports where increased iliopsoas strength would appear to offer benefits include cycling, rowing and mountain climbing, in particular when scaling rock faces.

The problem

The problem in developing hip flexor strength has been the lack of appropriate exercises. Two that have traditionally been used for this muscle group are incline sit-ups and hanging leg raises, but in both cases the resistance is basically provided by the exerciser's own body weight. As a consequence these exercises can make only a very limited contribution to actually strengthening the flexors.

Until now the only weighted resistance equipment employed for this purpose has been the multi-hip type machine. When using this multi-function apparatus for hip flexion the exerciser pushes with the lower thigh against a padded roller which swings in an arc. One difficulty with this apparatus is that the position of the hip joint is not fixed and thus it is difficult to maintain correct form when using heavy weights or lifting the thigh above the horizontal.

The solution

With the release of the MyoQuip HipneeFlex there is now a machine specifically designed to develop and strengthen the leg flexors. It exercises both hip and knee flexors simultaneously from full extension to full flexion. Because the biomechanical efficiency of these joints decreases in moving from extension to flexion, the mechanism is configured to provide decreasing resistance throughout the exercise movement and thus appropriate loading to both sets of flexors.

Hip Flexor exercises using the MyoQuip HipneeFlex

The exercise movement involves the feet being drawn back from a fully extended position to a fully flexed position. Thus both hip and knee flexors are exercised through a range where the included angle at the joints varies from 180º to around 30º.

The arc through which the foot engagement device moves is designed to closely parallel the path that the feet would normally traverse if drawn back without resistance. It also creates a natural tendency for the two joint angles to vary synchronously so that they are both under continual load.

Conclusion

The absence until now of effective techniques for developing the hip flexors means that we do not really know what benefits would flow from their full development. However, given that in elite sport comparatively minor performance improvements can translate into contest supremacy, it is an area that offers great potential.

40 Yard Dash

Preparation work

What time do I have available for training?

• how long before I have to put my improved acceleration & speed to the test
• how many days each week can I train
• how many times a day can I train

What facilities do I need?

• Somewhere to run - an Athletics Track or sports field
• Somewhere to do exercises - gymnasium
• Somewhere to do strength training - weight training room

What equipment do I need or have access to?

• Appropriate clothing for training in
• Exercises mat
• Free weights for weight training

The preparation of any training program is explained in more detail on the Planning page.

Training Plan Phases

Split the available training time into two equal periods (phases). If there are 16 weeks available for training then we have 8 weeks for Phase One and 8 weeks for Phase Two. This would allow for two four week cycles in each phase.

Phase One

The objectives of phase one are to develop general strength and general endurance. The workload in the first three weeks of the example plan below increase each week (easy, medium and hard) and the 4th week comprises of active recovery and tests to monitor training progress. The aim of the 4 week cycle is to build you up to a level of fitness (3 weeks), allow a recovery (1 week), build you up to higher level of fitness, allow a recovery, and so on.

Remember a training program is athlete specific and the results of the tests in the 4th week can be used to adjust the training in the next four week cycle to address any limitations.

The pace for each of the running endurance sessions should be between 15 and 20 seconds per 100 metres.

Each session should include an appropriate warm up and cool down program.

Week One

Mon	(am) Strength Training General - (pm) 5 km steady run
Tue	Endurance - 2 X 4 X 150 metres (23 to 30 seconds) Recovery of 2 minutes/repetition and 5 minutes/set
Wed	Strength Training General
Thu	Endurance - 2 X 3 X 200 metres (30 to 40 seconds) Recovery of 2 minutes/repetition and 5 minutes/set
Fri	(am) Strength Training General - (pm) 5 km steady run
Sat	Endurance - 2 X 3 X 250 metres (38 to 50 seconds) Recovery of 2 minutes/repetition and 5 minutes/set
Sun	Rest

Week 2

Mon	(am) Strength Training General - (pm) 5 km steady run
Tue	Endurance - 2 X 4 X 200 metres (30 to 40 seconds) Recovery of 2 minutes/repetition and 5 minutes/set
Wed	Strength Training General
Thu	Endurance - 2 X 3 X 250 metres (38 to 50 seconds) Recovery of 2 minutes/repetition and 5 minutes/set
Fri	(am) Strength Training General - (pm) 5 km steady run
Sat	Endurance - 2 X 3 X 300 metres (45 to 60 seconds) Recovery of 2 minutes/repetition and 5 minutes/set
Sun	Rest

Week 3

Mon	(am) Strength Training General - (pm) 5 km steady run
Tue	Endurance - 2 X 4 X 250 metres (38 to 50 seconds) Recovery of 2 minutes/repetition and 5 minutes/set
Wed	Strength Training General
Thu	Endurance - 2 X 3 X 300 metres (45 to 60 seconds) Recovery of 2 minutes/repetition and 5 minutes/set
Fri	(am) Strength Training General - (pm) 5 km steady run
Sat	Endurance - 2 X 3 X 400 metres (60 to 80 seconds) Recovery of 2 minutes/repetition and 5 minutes/set
Sun	Rest

Week 4

Mon	Strength Training General
Tue	Cooper Test or Multistage Fitness test
Wed	Strength Training General
Thu	400m drop off test
Fri	Strength Training General
Sat	Quadrathlon
Sun	Rest

Strength Training

Examples of general strength training are:

• Weight Training program - dumbbells
• Weight Training program - free weights and machines
• Weight Training program - sprinters

For young athletes, <17 years of age, I would recommend circuit training in place of the weight training.

Phase 2

The objectives of phase two are to develop specific strength, specific endurance and speed. The workload in the first three weeks of the example plan below increase each week (easy, medium and hard) and the 4th week comprises of active recovery and tests to monitor training progress. The aim of the 4 week cycle is to build you up to a level of fitness (3 weeks), allow a recovery (1 week), build you up to higher level of fitness, allow a recovery, and so on.

Remember a training program is athlete specific and the results of the tests in the 4th week can be used to adjust the training in the next four week cycle to address any limitations.

The pace for each of the running sessions can be determined from the calculator provided after the four week program.

Each session should include an appropriate warm up and cool down program.

Week 1

Mon	Strength Training Specific
Tue	Endurance Specific - 3 X 3 X 40 metres @ 90% effort Recovery of 90 seconds/repetition and 5 minutes/set
Wed	Strength Training Specific
Thu	Speed - 3 X 3 X 30 metres @ 100% effort Recovery of 5 minutes/repetition and 10 minutes/set
Fri	Strength Training Specific
Sat	Speed - 3 X 3 X 60 metres (20m @ 100% + 20m @ 90% + 20m @ 100%)  Recovery of 5 minutes/repetition and 10 minutes/set
Sun	Rest

Week 2

Mon	Strength Training Specific
Tue	Endurance Specific - 3 X 3 X 50 metres @ 90% effort -  Recovery of 90 seconds/repetition and 5 minutes/set
Wed	Strength Training Specific
Thu	Speed - 3 X 3 X 40 metres @ 100% effort Recovery of 5 minutes/repetition and 10 minutes/set
Fri	Strength Training Specific
Sat	Speed - 3 X 3 X 90 metres (30m @ 100% + 30m @ 90% + 30m @ 100%) Recovery of 5 minutes/repetition and 10 minutes/set
Sun	Rest

Week 3

Mon	Strength Training Specific
Tue	Endurance Specific - 3 X 3 X 60 metres @ 90% effort Recovery of 90 seconds/repetition and 5 minutes/set
Wed	Strength Training Specific
Thu	Speed - 3 X 3 X 50 metres @ 100% effort Recovery of 5 minutes/repetition and 10 minutes/set
Fri	Strength Training Specific
Sat	Speed - 3 X 3 X 120 metres (40m @ 100% + 40m @ 90% + 40m @ 100%) Recovery of 5 minutes/repetition and 10 minutes/set
Sun	Rest

Week 4

Mon	Strength Training Specific
Tue	Lateral change of direction test and Leg elastic strength test
Wed	Strength Training Specific
Thu	Flying 30m Test
Fri	Strength Training Specific
Sat	Running-based Anaerobic Sprint Test (RAST)
Sun	Rest

Strength Training

Examples of specific strength training are:

• Complex training (mix of plyometrics and weights).
• Plyometrics
• Plyometric Exercises - Arms
• Plyometric Exercises - Legs
• Plyometrics High Intensity Exercises - Legs
• Weight Training program - sprinters

For young athletes, <17 years of age, I would recommend circuit training in place of the weight training. The exercises need to be specific to the demands of your sport or event.

Plyometrics

Plyometric drills can be incorporated into the warm up. Conduct 2 or 3 sets over a distance of 20 to 30 metres. Focus on quality and not quantity. Example of plyometric drills are:

• Single leg hops over cones
• Double leg hops over cones
• Zig Zag hops (one legged lateral bounds)
• Alternate Leg running bounds (up stairs)

Sprint Technique

Development of your sprint technique is just as important as the development of your strength and endurance. Guidance on the correct technique for each phase of the sprint is detailed on the sprint technique page and the sprint start page. To assist in the development of your technique see the information contained on the technique trainingpage.

Technique Runs

As part of each track session, include at the start of the session 6 X 50 metres:

• 1st run only concentrate on running Tall
• 2nd run only concentrate on a running Relaxed
• 3rd run only concentrate on running Smoothly
• 4th run only concentrate on the Drive action
• 5th & 6th runs concentrate on them all

Speed

The researchers summarised their findings

The purpose of this investigation was to examine the relationship among 6 physical characteristics and 3 functional measures in college (US) football players. Data was gathered on 46 NCAA Division I college football players. The 3 response variables were 36.6m sprint (40 yards), 18.3m shuttle run, and vertical jump. The 6 regression variables were height, weight, percentage of body fat, hamstring length, bench press, and hang clean. A stepwise multiple regression analysis was performed to screen for variables that predict physical performance. Regression analysis revealed clear prediction models for the 36.6m (40 yards) sprint and 18.3m shuttle run. [1]

During recent years in the US, a system of selecting athletes for college and professional sports teams has evolved into several major physical tests involving speed, agility and strength given to athletes on the same day. These tests are called the "combines" in the USA. Having a good day at the combines can produce on the spot scholarships from large universities, and it can mean literally millions of dollars in sign-on bonuses and salaries for athletes entering the professional ranks. With the results of this new study, future "combines" may focus on two acceleration tests. In the USA, the 40 yard sprint is king for many sports, except baseball, which uses the 60 yard distance required to run bases.

Big Ticket Items in Teaching Acceleration Techniques

There are several acceleration techniques that can be taught in a few training sessions that will increase the speed of many athletes. Techniques like Ankle Dorsiflexion, Pocket Chin Arm Swings, Acceleration Position, and the grand prize of speed training is the Valsalva Acceleration Technique.

Dorsiflexion

Most untrained athletes run with their toes pointed downward. While they may have fast leg turnover, but just like throwing a ball without using the wrist, the power is missing unless the foot is dorsiflexed (pointing up) and ready to fire off the ground. Dorsiflexion of the ankle simply means to raise the toes and, in essence, cock the foot before striking the ground. This action engages the ankle and the foot for additional power generation and this can mean additional stride length for the athlete. The Claw Drill and many of the skipping drills teach athletes to dorsiflex their feet.

Pocket-Chin Arm Swings

Without exception, teaching proper arm mechanics for maximizing running speed is the most difficult. Many athletes do not see themselves unless they are taped and they frequently gauge what they are doing with their arms based on their perception of how their arms feel during sprinting. In most cases, arms swings are incorrect and need repositioning. "Pocket / Chin" is a good way of teaching arm mechanics and the Butt Bumpers drill is the best drill I have seen for teaching correct arm swing mechanics. Have your athletes sit on the ground with both legs straight in front (side-by-side) with arms locked at 90 degrees. In slow motion, have athletes swing one arm backward until the hand reaches the pocket, and one arm forward until the hand reaches chin level (approximately twelve inches away from the chin).

This is the "pocket / chin level" position. Performing this drill in slow motion initially is a good idea until the coach sees that the athletes are getting the feeling of the arm positions. Move to half speed, then to full speed for three sets of 5 to 10 seconds. If performed correctly, it is easy to see why this drill is called butt bumpers. In 1970 I was taught to run with arm swings pointed in a straight line forward. Now we know that this instruction slightly restricts the hips during running and thus, makes the athlete run slower. The arm swings should be pointed slightly toward the centre of the body in order to maximize the hips, which can increase stride length. Too much side-to-side will over rotate the hips and cause problems. If an athlete points the arms past centre of the body, this can make the feet push off the surface in a duck-footed style rather than push the athlete straight toward the target. When you see a problem with the feet, look to the arms first for correction as there may be an easy fix here. Challenge them to perform Pocket/ Chin drills with "locked 90 degree arms" at home looking in the mirror, sideways and front ways.

Acceleration Position

Due to the work of Brian Mackenzie coaches are hearing about the importance of proprioception training for sports. This term becomes very important in teaching the acceleration position. The number one mistake made by athletes trying to run faster, is to stand up too soon in fly phase running without going through the "drive phase," which is marked by an aggressive forward lean (at the ankles). The description of an airplane taking off, low at first, but slowing raising upward with effort made to not jump up to quickly and bump the passengers heads, seems to be an understandable analogy for most athletes. When performing the standard calf stretch, with one leg back and one forward, while leaning on a fence is a good way to reinforce the acceleration position -- straight back, bent at the ankles.

Valsalva Acceleration Technique

A slower athlete can beat a faster athlete to the ball, to the hoop, to the tackle, to the touchdown, and to the finish line if the slower athlete is trained to hit the acceleration position (body straight, forward lean from the ankles) with arms pumping pocket-to-chin level and tactically using the Valsalva acceleration technique at precise points.

If you look up Valsalva manoeuvre on the internet, you will find that this describes briefly holding the breath. When applied properly for a brief burst of 2.5 seconds, this technique can be the greatest single producer of an instantaneous explosion in force, speed and strength known in science. Like many techniques, this one is so powerful that it can cause harm but it also delivers championship plays.

We all use the body's natural ability of increasing strength by unconsciously performing the Valsalva manoeuvre. My favourite analogy to explain this to athletes is to describe a situation where the athlete's mom hands the athlete a jar with a tight lid. Mom needs some extra strength to open the jar so she calls on the athlete for help. On first attempt, the lid is too tight for the athlete. On second attempt, the athlete increases the intensity and pushes hard with maximal effort.

If you will think about what the body does naturally in this situation, you will understand this valuable technique. The athlete tightens the abs, and holds the breath for 2 or 3 seconds as max effort is applied. This is the Valsalva manoeuvre. The body increases blood pressure by additional 100 points very quickly with this natural action. Clearly, this is dangerous to older adults with potential for stokes and it can be dangerous to some young athletes. But this technique will assist an athlete to open the jar, lift more weight maximally, and to beat a faster athlete to the ball, goal or finish line.

An athlete can not perform a maximum lift while inhaling. Nor can an athlete quickly accelerate with maximum force while inhaling. The body is designed for the Valsalva manoeuvre and needs to be trained how and when to deploy the technique.

Valsalva Acceleration Strategy

Holding the breath too long can cause harm by making an athlete actually pass out. One occurrence is reported in the literature where this technique was responsible for bursting a tiny blood vessel in the eye of an athlete during heavy maximal lifting.

It is easy to observe that the Valsalva manoeuvre is frequently used safely as a natural function of the body to increase strength, but it is only held for two to three seconds naturally. A 100 meter sprinter would have time to plan for four Valsalva acceleration techniques during the short ten second event, or a masters sprinter like me, may get in five before the finish. The miler may place the Valsalva acceleration technique in the race strategy 100 meters before the finish line to power that extra kick.

The 400 meter sprinter may want to deploy this technique during the four handoff zones during the single lap around the track. The baseball player may want to deploy this acceleration skill twice during the seven second trip to first base.

The football player may strategically use the Valsalva technique to break on the ball for a surprise steal. The applications for this acceleration technique are endless.

Conclusion

We have all seen the superstar athlete interviewed on television after making a game winning play.

"How did you make that great play?" asks the reporter.

"I knew that the game depended on it. I gave it everything I had, and I made the play" seems to be the frequent answer. That is what we hear, but the athlete should have explained:

"I wanted to make the play so I made the extra effort to get into the acceleration position (with a straight body bent from the knees), pumped my arms pocket-to-chin level, and I positioned my shoulders lower to the ground than my competitor to drive my body forward toward the target, I took the extra energy necessary to apply the Valsalva technique to temporarily raise my blood pressure by an extra 100 points so I could get there faster then my competitor."

Some athletes make great plays without knowing the science of acceleration, but what if all your athletes trained with these techniques throughout the season. Perhaps this technique explains why some teams that do not match the physical attributes of stronger teams, still find ways to win championship. Perhaps the inferior team realised that they had to go deep inside, work hard, get into the acceleration position on every play, and use the Valsalva technique more to beat the superior team. "Who wants the victory the most, will win this game" is what we say to the team. Perhaps we should train athletes to use this natural technique designed to assist the body to get into maximal effort so athletes will have the skills necessary to beat a faster athlete and not wait until it is the game winning play to deploy it. I rest my case. Speed is a skill and skills can be improved.

Agility

The components of agility

The multi dimensional movement demands of field and court games dictate a revaluation of the traditional approach to the development of agility. This demands a systematic multi factored approach that results in significant improvement in game speed. Possibly we have put the cart before the horse by training agility in isolation without considering the underlying coordinative abilities and strength. Full development of coordinative abilities provides a repertoire of motor skills that can be adapted to deal with sport specific movement demands. According to Drabik [1] the coordinative abilities are:

• Balance - Maintenance of the centre gravity over the base of support. It has a static and a dynamic quality
• Kinaesthetic Differentiation - Ability to feel tension in movement to achieve the desired movement
• Spatial Orientation - The control of the body in space
• Reaction to Signals - The ability to respond quickly to auditory, visual and kinaesthetic cues
• Sense of Rhythm - The ability to match movement to time
• Synchronization of movements in time - Unrelated limb movements completed in a synchronized manner
• Movement Adequacy - Ability to choose movements appropriate to the task

The coordinative abilities never work in isolation, they are all closely related. They are the underlying foundation for agility and the prerequisite for technical skills.

Strength is fundamental

Agility, by the nature of its demands in terms of stopping and starting, requires good basic strength. Without adequate leg strength there is a limit to the quality of the movement which will significantly affect the ability to train. Leg strength must be developed in parallel with agility work. The forces involved in multiple planes also demand that we take a less traditional approach to the development of leg strength that will transfer to the movement skills. Begin with body awareness and control in conjunction with strength training. It is not an overnight affair, but part of a longer term systematic development program, based on fundamental movements and the subsequent refinement of those movements. Build progressively into sport skills. Carefully understand the movement patterns of the sport and their position within the sport. Each sport has certain movement commonalities with other sports. Look for those commonalities. Each sport will also have movements that are unique to that sport so understand those and prepare for them. Equipment will often dictate movement patterns and positions i.e. the glove in baseball, the stick in field hockey and ice hockey, the ball in rugby and football. Therefore train and test agility incorporating the game equipment to get a more accurate picture.

Is playing the sport enough to develop agility?

There is one school of thought that feels it is unnecessary to do any significant agility work outside the practice of the actual sport. The thought process is that practicing the movements outside the sport are non specific work that will not transfer and that it is impossible to duplicate the intensity of the actual practice or a game. I do not share that viewpoint. It is necessary to carefully design drills that tap into the repertoire of motor skills developed through the development of the coordinative abilities that make up the components of the movements required in the specific sport. The overload should be progressive and based on sound motor learning principles, sound biomechanics and adapted to each individual athlete.

Developing appropriate exercises

The approach is to design a hierarchy of exercises that lead seamlessly into the sport's skills. That hierarchy is:

• First Derivative - The actual movement done at game speed
• Second Derivative - The movements broken into component parts
• Third Derivative - Basic movements (coordinative abilities) that underlie the skill

Understanding the derivatives means understanding the breakdown of the movements in the respective sport.

Analyse the moments

Use game analysis to determine the movements and game speed. Game analysis will also determine the volume of work in the actual sport, which will in turn determine training volumes and intensities. Essentially what we are trying to do is take the guesswork and opinion out of the whole process so as to be as exact and precise as possible in the selection and prescription of exercise in order to produce an adaptive response that will transfer to the game. I personally have spent too much time drilling for drill sake. Agility drills with a million cones and sticks look good but what is the benefit? The player gets good at the drill, but the drills do not transfer to the game. The goal with agility drills should be efficient, effortless, flowing movement that transfers directly to the sport. Time the drills whenever possible to provide feedback to the player.

The components of agility training are:

• Body Control & Awareness - The ability to control the body parts and maintain a high level of awareness of those parts in relation to the goal of the movement.
• Recognition and Reaction - Recognition is the domain of the actual sport skills involved. Recognition of patterns and cues keys reaction. Reaction is the ability to respond quickly to the required stimulus.
• Starting - The ability to over come inertia. In multi-direction sports starts can be stationary or moving or a combination depending on the sport.
• Footwork - The hip to foot relationship. Conceptually agility is built from the ground up therefore footwork is the unifying thread in all agility work.
• Change of Direction - Initiated by getting the centre of gravity outside the base of support and then regaining control to maintain control and move in the intended direction. Change of direction involving stopping, which is the key to agility, also incorporates the ability to restart when necessary, regardless of the position of the body.

All these components can be significantly improved through systematic application of specific drills. The application of speed to sports that require multi-dimensional movements demands an understanding of the concept of game speed. Game speed is not linear track speed. It is the ability to apply all elements of speed to the demands of the game. In fact some of the technical aspects of speed that are rewarded in the sprint events in track and field can be counterproductive to game speed. Very little movement in multi-directional sports is straight ahead for any significant distance. Most movement involves angles, curves, starts, stops and direction changes. Agility and game speed are closely related. Agility is defined as the ability to recognize, react, start and move in the required direction, change direction if necessary and stop quickly. This typically occurs in a time frame of two to five seconds.

How to improve agility

Agility can be significantly improved if we understand and apply some basic principles/concepts:

• Skill - Open skill occurs when the movement goal is unknown. In a closed skill the movement is pre-programmed. The progression in agility training usually proceeds from closed to open skills.
• Reaction versus reflex - Reaction is the response to a stimulus to initiate movement. It is a conscious act that can be improved through training. Reflex, on the other hand, occurs at the sub cortical level and cannot be trained.
• Speed as a motor task - A motor task can be learned; therefore speed can be taught if the motor tasks involved are clearly defined.
• Practice
• Massed - the skill is practiced until learnt without taking a break. These sessions are good for athletes with high level of fitness and experience and are most suited to fixed practice.
• Distributed - practice is interspersed with breaks which can either be rest or another skill.

These sessions are good for athletes with lower levels of fitness and experience and are most suited to variable practice.

Strength qualities related to agility

Effective starting demands a high level of concentric strength to overcome inertia. It is extension of ankle/knee/hip pushing back against the ground to propel the body in the intended direction. Effective stopping demands a high level of eccentric strength demands. It is the proportionate bending of the ankle/knee/hip. Basic strength is a prerequisite for force production and reduction.

Eccentric strength, the primary requirement to stop effectively, is the ability to reduce force. It also requires tremendous joint stability and control. Force must be produced and reduced in extremely short time frames therefore the premium is on rate of force development. It is the ability to handle forces in an eccentric mode up to 12 times body weight and be able to change direction and overcome those forces. This all must be done in tenths of a second. It is developed through exercises that develop unilateral and reciprocal leg strength.

The following table shows the relationship of the strength qualities to the components of agility.

Basic Strength	F O O T W O R K	Balance, Body Control and Awareness
Speed Strength & Plyometrics		Starting and Acceleration Speed Angles & Vectors
Power Endurance		Complex Footwork
Maximum Strength		Change of Direction, Stopping

These qualities must be developed in parallel, not in isolation and then put back into the whole. There is overlap and interdependency. The traditional approach was to develop strength through repetition of the movement. Theoretically as the athlete got stronger the movement got better, but it did not. The bad habits and patterns that developed due to improper strength resulted in poor movement mechanics. So even though the athlete was doing the drill, the transfer was negative. Incorrect repetitions led to the acquisition of faulty movement patterns that impede the formation of correct skills. A more rational approach demands mastery of prerequisite fundamental movement skills that are within the strength capabilities of the athlete. As the athletes strength increases through a systematic strength development program the complexity of the movements can change in parallel. Given the large window of adaptation open to the developing athletes this can occur quite rapidly.

What is agility work?

Agility work is not conditioning, it is speed development work. That statement has many profound implications. Movements must be mastered before any element of fatigue is brought into the picture. Old myths die hard! Grass drills, matt drills, line drills, agilities until you are ill have no foundation in training theory. In fact this approach is counterproductive in terms of sound motor learning. Incorrect movement patterns are learned and grooved. Does fatigue or so called pressure training fit into the picture? There is no question that the plants, cuts, starts and stops must be able to be done in a fatigued state. But that is not where you start, add reaction, add game situations and then add fatigue when the movements are mastered.

Mix reaction speed and agility

Perhaps the biggest shortcoming in most agility work is the lack of a reaction component. Research out of Australia has shown significantly different patterns of activation on simple cutting tasks done with reaction than the same tasks done without reaction. In short reaction changes everything. Reaction can be incorporated early and often if it is placed as part of a logical progression. Reaction should be practiced to the dominant cue demanded by the game.

Reaction can be to one of the following stimuli:

• Visual - Tracking ability, Narrow versus wide focus
• Auditory - Different cadences and tones
• Kinaesthetic - Pressure, pushes, bumps and surfaces

Conclusion

Agility is the key to game speed. It not only has a performance enhancement component, but it can make a huge contribution to injury prevention. An athlete who is more agile will be able to safely get into and out of positions that would otherwise be impossible. This can only be developed through a systematic approach that has a foundation in sound motor learning principles.

Energy

A 15m sprint every 90 seconds

English researchers Reilly and Thomas (1976) (7) investigated the patterns of football play in the old first division. They found that a player would change activity every 5 to 6 seconds, and on average he would sprint for 15 metres every 90 seconds. They found the total distance covered varied from 8 to 11km for an outfield player - 25% of the distance was covered walking, 37% jogging, 20% running below top speed, 11% sprinting and 7% running backwards. Ohashi and colleagues (5), researching football in Japan, confirmed these findings, showing 70% of the distance was covered at low to moderate pace below 4m/s, with the remaining 30% covered by running or sprinting at above 4m/s. Thus, for example, if a football player covers 10km in total, around 3km will be done at fast pace, of which probably around 1km will be done at top speed.

The pattern of football play has also been expressed in terms of time. Hungarian researcher Peter Apor (1) and the Japanese researchers (5) both describe football as comprising sprints of 3 to 5 seconds interspersed with rest periods of jogging and walking of 30 to 90 seconds. Therefore, the high to low intensity activity ratio is between 1:10 to 1:20 with respect to time. The aerobic system will be contributing most when the players' activity is low to moderate, i.e. when they are walking, jogging and running below maximum. Conversely, the ATP-PC and anaerobic glycolysis systems will contribute during high-intensity periods. These two systems can create energy at a high rate and so are used when intensity is high. The above research has described the average patterns of play during football and from this we can reasonably deduce when each of the energy systems is contributing most. However, now we need to establish just how important each energy system is for success.

Recovering from high-intensity bursts

There is evidence that the aerobic system is extremely important for football. Along with the fact that players can cover over 10km in a match, Reilly (6) found heart rate to average 157 bpm. This is the equivalent of operating at 75% of your VO2max for 90 minutes, showing that aerobic contributions are significant.

This is confirmed by the fact that various studies have shown footballers to have VO2max scores of 55 to 65 ml/kg/min. These VO2max scores represent moderately high aerobic power. Reilly and Thomas (1976) (7) showed that there was a high correlation between a player's VO2max and the distance covered in a game. This was supported by Smaros (1980) (8) who also showed that VO2max correlated highly with the number of sprints attempted in a game. These two findings show that a high level of aerobic fitness is very beneficial to a footballer.

The greater the player's aerobic power the quicker he can recover from the high-intensity bursts. These short bursts will be fuelled by the ATP-PC and anaerobic glycolysis systems. Then, during rest periods, a large blood flow is required to replace the used-up phosphate and oxygen stores in the muscles and to help remove any lactate and hydrogen ion by-products. The quicker this is achieved, the sooner a player can repeat the high-intensity sprints, and thus cover more distance and be able to attempt more sprints. Therefore, the aerobic system is crucial for fuelling the low to moderate activities during the game, and as a means of recovery between high-intensity bursts.

Which system fuels the sprints?

As already mentioned the ATP-PC and anaerobic glycolysis systems fuel the high-intensity periods. However, if we are to optimize training programs, we need to know whether in performing the high-intensity bursts both systems contribute evenly or whether one is more important. As the sprints a player makes are mostly 10 to 25 metres in length, or 3 to 5 seconds in duration, some researchers have assumed that the ATP-PC system will be the most important. However, since football has an intermittent intensity pattern, just because the sprints are brief does not mean that anaerobic glycolysis does not occur; research has shown that anaerobic glycolysis will begin within 3 seconds. To determine whether anaerobic glycolysis is significant during football, researchers have analysed blood lactates during match play. However, results from these studies have varied. Tumilty and colleagues (9) from Australia cite research varying from 2 mmol/l, which is a low lactate score indicating little anaerobic glycolysis, to 12 mmol/I, which is quite a high score. Most studies seem to find values in the 4-8 mmol/I range, which suggests that anaerobic glycolysis has a role.

The contrast in results is probably due to the varying levels of football in the different studies. Some use college-level players, others professionals. Some studies test training games, others competitive matches. This is likely to confound results. Ekblom (2), a researcher from Sweden, clearly showed that the level of play was crucial to the lactate levels found. Division One players showed lactate levels of 8-10 mmol/1 progressively down to Division Four players showing only 4 mmol/1. Tumilty and colleagues (9) conclude that the contribution of anaerobic glycolysis remains unclear, but is probably significant. They suggest that the tempo of the game may be crucial to whether anaerobic glycolysis is significant or not. As Ekblom noted: "It seems that the main difference between players of different quality is not the distance covered during the game but the percentage of overall fast-speed distance during the game and the absolute values of maximal speed play during the game".

The conclusion from these lactate studies is that, as the playing standard increases, so may the contribution of anaerobic glycolysis. However, I think more precise research is needed to determine exactly how fast and how frequent the high-intensity efforts during play are. Maximum-intensity bursts with long recoveries will emphasis the ATP-PC system, whereas high-intensity but not maximal bursts occurring more frequently will emphasise the anaerobic glycolysis system more. Thus, along with the standard, the style of play and football culture may also influence the physiological demands. This means that the country in which the researchers are based may affect the conclusions they draw when studying the relative contributions of the two systems.

What action to take

From the research completed so far, it would probably be fair to conclude that for the high-intensity bursts during play both the anaerobic glycolysis and the ATP-PC systems contribute, but that the ATP-PC system is more important. This is because the ratio of high-intensity to low-intensity activity is between 1:10 and 1:20 by time. The high-intensity periods are very short and the rest periods relatively long. Therefore, the ATP-PC system will probably be more useful and also has sufficient time to recover. Research has also shown that lactate values become moderately high but not so high as to indicate that the anaerobic glycolysis system is working extremely hard. Indirectly, this is confirmed by Smaros (8) who showed that glycogen depletion was mostly in the slow-twitch muscle fibres, which suggests that glycogen is being used for the aerobic system but not the anaerobic system. However, the possibility exists that for professional-standard football, or football played at a high tempo, anaerobic glycolysis will be at least as significant as ATP-PC.

If coaches of professional teams want to know better which system is more important, then more research taking place in their own country and using top players as subjects is needed, accurately analysing intensity patterns in match play and measuring lactate levels. Until then, training regimes must cater for all three systems, with particular attention to the aerobic and ATP-PC systems. Japanese researchers (3) performed a Maximal Intermittent Exercise (MIE) test on footballers that consisted of 20 x 5 seconds maximum efforts with 30 seconds active rest. This was meant to mimic a high-intensity section of the game. They correlated the performance on this test with fitness tests representing the three energy systems, VO2max for the aerobic system, lactic power for the anaerobic glycolysis system, and maximum power for the ATP-PC system. All three components of fitness were significant to the performance on the MIE test. Peter Apor (1) agrees with this in making fitness recommendations for footballers, saying that a good aerobic fitness needs to be linked to a moderate anaerobic glycolysis power and a high ATP-PC power.

A specific type of interval training for footballers would be to mimic the demands of an actual game with the correct work-to-rest ratios and distances covered. If players sprint for over 1 km during a game with high to low ratios of 3 to 5 seconds to 30 to 90 seconds, then a session such as two sets of 20 x 25m maximal sprints with 30 seconds rest (2 minutes between sets), would represent the demands of a tough match, namely, frequently repeatable high power. To focus solely on the ATP-PC system, short maximal sprints of 20 to 60 metres with 1 to 2 minutes recovery are best. To train the anaerobic glycolysis system, longer sprints of 15 to 30 seconds, with 45 to 90 seconds recovery, are recommended. Aerobic training involves running continuously, fartlek, long repetitions (e.g., 6 x 800 metres, 1 minute rest) or extensive intervals at moderate speeds (e.g. 30 x 200 metres, 30 seconds rest). Trainers should be aware that running sessions, intervals and shuttle runs (or doggies) should be carefully planned so that they target the correct energy system. Running speeds, distances and rest periods should be calculated so that the session will target the specific energy system the coach wants to develop.

Fluid Replacement

Nutrition

Every club expects the players to train, but it hardly seems worthwhile insisting on this if the opportunities offered by good nutrition are neglected. One of the key areas where nutrition can have a direct impact on performance is in the area of hydration. There is good evidence that players who become dehydrated are more susceptible to the negative effects of fatigue, including loss of performance and increased risk of injury. There is also growing evidence that excessive sweat losses, especially high salt losses, can be a factor in some of the muscle cramps that affect players in training and competition.

Recently, however, a number of clubs have recognised that hydration is important and that no single strategy suits all players in all environments. This has led to an assessment of individual needs so that a personal drinking strategy can be put in place. This practice appears to have gained ground in American football, where pre-season training typically takes place in extreme heat and involves two sessions per day. In recent years, a number of high-profile fatalities, including that of Korey Stringer in the NFL, have raised the awareness of what can happen when things go seriously wrong. Several of the top English football clubs now have monitoring strategies in place.

Zero-cost analysis

At its simplest level, weighing of players before and after training gives an indication of their level of dehydration and risk of heat illness. This takes account of both the amount of sweat lost and the amount of fluid drunk and gives the net balance. There will be a small amount of weight loss due to the fuels used to produce energy (mostly carbohydrate, with a bit of fat), but this amount is relatively small. There will also be water loss from the lungs and loss through the skin. Broadly speaking, a weight loss of 1kg represents a net loss of 1L of body fluid.

A slightly better measure is obtained if the player is weighed before and after training or competition (nude and dry on both occasions) and his (or her) drinks bottle is also weighed before and after, assuming that all players drink from their own bottles and that anything that is taken from the bottle is swallowed and not spilled/poured over the head/spat out. If the decrease in weight of the drinks bottle is added to the decrease in weight of the player, we get the actual sweat loss. We also get a measure of the player's drinking behaviour.

All of this is easy to do, and all it requires is a set of kitchen scales to weigh the drinks bottles, a reliable set of scales to weigh the players, and a bit of organisation. The cost is effectively nil -just a bit of time and effort on the part of one of the backroom staff. There is one more measure that can be usefully added, but this needs rather more specialised apparatus and is thus likely to be the preserve of the top clubs only: the measurement of salt losses in sweat.

Identifying salty sweaters

There are many ways to measure salt losses in sweat. The one that is most convenient in practice is to use gauze swabs covered with an adhesive plastic film: typically, four are applied at different sites before exercise begins and left in place for an hour or so. After they are removed, the amount of sweat and the amount of salt in the patch can be measured, allowing the 'salty sweaters' to be identified.

We have made these measurements on the first team squads at a number of Europe's top teams, typically testing about 20-30 players at each club. They results have been consistent between clubs when the training sessions have been similar, but the variability between individual players has been striking. Key findings in a typical 90-minute training session are as follows:

1. Average sweat loss is typically about 2L, but this can vary from about 1L to over 3L, even though all the players are doing the same training in the same conditions and are wearing the same amount of clothing.
2. Average fluid intake is typically about 800-1,000ml, but this can vary from about 250ml to over 2L.
3. There is no relationship between the amount of sweat a player loses and the amount he drinks.
4. The sweat salt content varies greatly: the better acclimatised players have lower sweat content, but again there is a large individual difference. Sweat salt (sodium chloride) losses can reach almost l0g in a single training session in some players, and this during twice-a-day training. Others lose only small amounts - 2g or less in the same training session.
5. When training takes place in the cold, sweat losses may be almost as high as when training in the heat, but players drink far less and so end up just as dehydrated - or even more so.

These findings may appear simplistic and predictable - apart from the last one, which is not intuitively obvious - but they give the training staff of a club that is serious about maximising its human assets a chance to prescribe fluid according to the player's needs. The aim should be not to drink too much, as some players do, but to drink enough to limit weight loss to no more than 1-2% of the pre-exercise weight.

There is also a suspicion - and I should stress it is no more than a suspicion at present - that players with a very high sweat salt content are more prone to cramp and that this risk can be reduced by salt supplements.

These simple steps can make a difference between being able to score that vital goal in the last minute and being a virtual spectator. It is only surprising that it has taken the world of professional football so long to realise this.