Stretching And The Risk Of Injury

[mtex]

Many athletes engage in at least some form of stretching before exercise, at least partly in the belief that loosening their muscles and connective tissues will lower their risk of injury. Such faith in stretching seems logical: after all, shouldn't loose muscles be less susceptible to excessive strain during workouts, compared to sinews that are as tight as violin strings?
Although the idea that stretching can help promote injury-free training is widely accepted among athletes and coaches, scientific support for the notion has been quite modest, and in fact one key study actually linked stretching with a higher frequency of muscle and connective-tissue problems.

Before we take a close look at that investigation and several other key studies on stretching, we should bear in mind that stretching research has traditionally fallen into two key categories: (1) randomized, controlled trials, and (2) cohort studies. In the former, the somewhat homogeneous individuals taking part in the study are randomly divided into two groups, and one group then stretches regularly as a normal part of training while the other group goes 'cold turkey'. This is actually the best way to get a feeling for stretching's efficacy, because it tends to eliminate various forms of bias which could significantly distort the results of the research.

Cohort studies are usually easier to carry out, however, and as a result they appear much more often in the scientific literature. In cohort-style research, scientists would simply follow athletes who routinely do or do not stretch over time to determine which group had a higher incidence of injury. Naturally, such cohort investigations are susceptible to considerable bias.

For example, let's say you that you were an exercise scientist and that you began tracking all the players in the Premier football division, keeping close tabs on their injuries. Of course, at the beginning of your cohort research you would have each athlete fill out a questionnaire in which he described his stretching habits in detail. You could then categorize the players as regular stretchers or non-stretchers (and perhaps eliminate from consideration individuals who stretched rather sporadically) and simply record the number of significant injuries sustained by members of the two groups over the course of a season. You might get fancier still and sub-divide the two groups into strikers, midfield players, and defenders if you wanted, to see whether team position had an effect on injury rates or interacted with stretching in some way. At any rate, at season's end you would have a very good feeling for whether stretchers or non-stretchers were injured more frequently.

Was it stretching - or something else?
Trouble would arise, however, when you tried to interpret your results. For example, let's say that you determined that athletes who stretched in a systematic and regular manner had significantly fewer injuries, compared to individuals who didn't stretch. What would this actually mean?

In other words, was it really the regular stretching that kept injuries at bay - or some other factor? Since these particular footballers indicated that they were quite scrupulous about their stretching, it's possible that they were also doing other things which decreased their risk of getting hurt. Perhaps they were warming up more thoroughly before training sessions and matches, for example, a practice which might also lower injury incidence. Or perhaps, given that they were so serious about stretching, they were also more careful about their diets, ingesting more protein, carbohydrate, vitamins, minerals, and antioxidants, compared to individuals who ignored stretching. Possibly, they were getting more sleep or even carrying out slightly more effective strength training, too. As you can see, many potential sources of bias could be present, and so it would be very difficult to proclaim that stretching was the 'magical injury-fighting pill' which kept these athletes out of trouble.

Further problems
If you found that your stretchers and non-stretchers had similar injury rates, it might be because stretching was ineffective as an injury-prevention technique, but it might also be true that stretching actually lowered injury rates in 'tight' soccer players who sensed they needed stretching, making their injury rates comparable with the flexible people who didn't feel a need to stretch. And if non-stretchers had a lower frequency of injury, you might conclude that stretching actually increased the chance of muscle trauma, but it might also be the case that the timing of stretching was wrong, an improper form of stretching was utilized, or that stretching did lower injury rates - but not enough to make stretchers as injury-resistant as the naturally lax athletes (an easy-to-see bias in these cohort studies is that many individuals who stretch probably do so for a reason - because their muscles are unusually tight; individuals who don't routinely stretch may avoid stretching because they are naturally flexible, and it may be these intrinsic factors (tightness and flexibility) which ultimately determine injury rates, not the selection or avoidance of stretching). An additional worrisome factor is that athletes might have been somewhat dishonest about their stretching habits (since you had undertaken a cohort study and had no direct control over how the athletes actually stretched and trained, there would be little way of knowing whether the players were actually doing what they said they were doing). If enough athletes distorted their stretching habits, your results would also be distorted.

As you can see, cohort studies have lots of problems! Incidentally, there are four cohort studies concerning stretching and injury in recent, peer-reviewed, high-quality scientific journals, and not a single one of these investigations documents a protective effect for stretching. It would be easy to conclude from these four works that stretching has little impact on injury, but consider the above comments about cohort studies before you make that kind of 'leap of faith'.

What happened in Australia
Randomized controlled trials might help clear up the picture, but unfortunately there are only two such studies in the literature. In one of them, 1093 male army recruits were randomly divided into stretch and control groups ('Effects of Flexibility and Stretching on Injury Risk in Army Recruits,' Australian Journal of Physiotherapy, vol. 44, pp. 165-172, 1998). Recruits in the stretching group unkinked their calf muscles during their warm-ups, while control-group subjects did not. At the end of the experimental period, the total frequency of five different types of lower-leg injury in the stretch group was 4.2 per cent, compared with 4.6 per cent for the control group, but the difference was not statistically significant.

In the second study, 1538 male Australian army recruits were randomly allocated to stretch and control groups ('A Randomized Trial of Preexercise Stretching for Prevention of Lower-Limb Injury,' Medicine and Science in Sports and Exercise, vol. 32(2), pp. 271-277, 2000). In case you are wondering why army recruits seem to be the sole providers of randomized, controlled information about stretching and injury, bear in mind that such novitiates exercise rather intensely during their basic training, their rate of lower-limb injury is very high, and they also represent a captive audience on whom experimental manipulations can be easily imposed and monitored. They are thus 'perfect subjects' (from a pure research standpoint), but bear in mind that army neophytes are not necessarily in great shape - nor do they train like typical endurance athletes, and thus the results may not apply very well to experienced athletes with superior functional strength and overall fitness.



Marching, running, swimming - you name it
In this second study, recruits in the stretch group statically loosened six key lower-limb muscle groups (gastrocnemius, soleus, hamstrings, quads, hip adductors, and hip flexors) every other day - prior to training - for 20 seconds each. The fitness, age (which ranged from 17 to 35 years), height, weight, body-mass index (BMI), and day of enlistment were recorded carefully for all subjects (the first five factors have been associated with injury risk in various pieces of scientific research; day of enlistment was included because - anecdotally - Australian-army-recruits' injury rates seem to rise later in the year). The training lasted for 11 weeks and included 40 training sessions (about four per week) totalling 50 hours of exercise. Training activities included marching while carrying a rifle and backpack (10 hours), running over distances ranging from four to eight kilometres (10.5 hours), negotiating obstacle courses (12.5 hours), carrying out circuit training (7.5 hours), swimming - plus pool-side press-ups and sit-ups (four hours), and battle training (wrestling, log lifting, fireman's-lift training, and shoulder rolls), which added on another 5.5 hours. Stretch-group members interspersed four minutes of light jogging and side-stepping with their stretching routines (this generally meant 40 seconds of jogging and side-stepping in between the 20-second stretches). Control-group recruits did carry out the warm-up jogging and side-stepping but completed no static stretching at all.

So who got hurt?
Over the course of the 11-week study (which incorporated a total of 60,013 hours of training), there were 175 lower-limb injuries in the control group and 158 maladies in the stretched recruits. The overall injury rate was 5.5 injuries per 1000 hours of physical training, or one injury every 181 hours (by the way, this is not dissimilar to the rate of injury commonly observed in regular endurance runners). Although the total number of injuries was slightly higher in the control group, regression analysis revealed that there was no statistically significant difference in injury rates between the groups, either for skeletal or soft-tissue injuries.

Although the limited stretching regime had no effect on risk of injury in these Australian recruits, there were three factors which were decent predictors of injury - day of enlistment, age, and performance on the '20-metre shuttle-run test'. The later in the year a recruit enlisted, the greater was his risk of injury, for reasons unknown. The older the recruit, the higher his chance of spraining an ankle, ripping up some thigh muscles, or stirring up a bout of significant knee pain (for obvious reasons). The best predictor of all, however, was fitness: the fitter the recruit (at least, as measured by performance during the 20-metre shuttle-run test), the smaller the chance of getting hurt, both for bony injuries and soft-tissue damage. Incidentally, in case you are concerned about whether the 20-metre shuttle run represents a reasonable method for determining fitness, research has indicated that it is indeed a reliable and valid indicator of both maximal aerobic capacity and running ability ('Validity of the 20-Meter Shuttle Run Test with 1 Min Stages to Predict VO2max in Adults,' Canadian Journal of Sport Science, vol. 14 pp. 21-26, 1989).

How the shuttle run works
At this point, you might be surprised about how hard it is to detect any injury-preventing properties for stretching (all four cohort studies and both randomized, controlled investigations have failed to indicate that stretching is good for injury prophylaxis) - and you might well wonder why the 20-metre shuttle-run test is such a great foreteller of injury (you might even be wondering what the test actually is). To understand the value of the shuttle run, bear in mind that it is a test in which athletes must repeatedly run back and forth between two lines which are exactly 20 metres apart. As they bop back and forth, they must touch one of the 20-metre lines at approximately the same time that a sound signal emanates from a pre-recorded tape. Challengingly, the frequency of this sound signal increases in such a way that running speed between the lines must be increased by .5 kilometres per hour (8.33 metres per second) every minute (the starting speed is set at 8.5 kilometres per hour). The test ends when an athlete is no longer able to keep up with the required pace ('The Multistage 20 Metre Shuttle Run Test for Aerobic Fitness,' Journal of Sports Sciences, vol. 6, pp. 93-101, 1988).

While the initial speed of 8.5 kilometres per hour is rather modest (it equates with 11.3 minutes per 1600 metres or 2:50 per 400 metres), the pace picks up fairly quickly, and the athlete who is fit and nimble enough to keep scrambling back and forth for 20 minutes can reach a speed of 20 kilometres per hour (333 metres per minute, or 4:48 per 1600 metres) before falling into a heap. As mentioned, an athlete's score on this test is a very reliable predictor of VO2max.

Coordination of movements is important
To understand why the shuttle test works as an injury predictor, note that athletes who fare very well on the shuttle run must have (1) a decent aerobic capacity (so that they can exercise continuously and at a fairly high intensity during the test), (2) good strength (so that they are less vulnerable to fatigue as the test progresses and so that they can accomplish all the braking and turning near the 20-metre lines without becoming completely exhausted), and (3) excellent coordination (to carry out the turn-arounds, accelerations, and decelerations without losing time due to sloppy movements). Of course, aerobic capacity is a reflection of overall muscle health. Good strength translates into better protection of bones, joints, ligaments, tendons, and even muscles during movement, which should decrease the risk of getting hurt. Outstanding coordination should have the same effect, because it would automatically reduce the stress placed on muscles and joints during activity (without coordination, a joint might be put through too-large a range of motion, or a muscle group might be forced to exert excessive force to correct the movement of a body part which had moved too far beyond its usual position). Studies of individuals recovering from low-back pain and injury reveal that often improvement in the coordination of movements involving the low back is more important than merely upgrading the strength of the low back for alleviating symptoms.

While this big Australian study suggests that stretching is a pretty ineffective way to lower the risk of injury (and that if you want to avoid getting hurt, high fitness, strength, and coordination are paramount factors), a number of criticisms can be raised. First, the stretches were somewhat short in duration (just 20 seconds). While there is no real consensus about how long individual stretches should be carried out, many athletes take considerably longer than 20 seconds to unkink tight parts of their body (stretching durations from 30 to 60 seconds are commonly recommended).

Fifteen seconds as good as two minutes
However, scientific research is not at all kind to the idea that more than 20 seconds are required to loosen up particular muscle groups. For example, in classic scientific research carried out at the Stanford University School of Medicine, 72 men were randomly divided into four groups: Members of one group statically stretched their hip adductors for 15 seconds at a time, individuals in a second group stretched for 45 seconds, and men in a third group attempted to loosen their adductors for two minutes at a time (a fourth, non-stretching group served as a control). As it turned out, there was ultimately no difference in hip-adductor flexibility between the groups, i.e., 15 seconds of stretching was just as effective as two minutes, in terms of untightening the adductor muscles ('Effect of Duration of Passive Stretch on Hip Abduction Range of Motion,' The Journal of Orthopaedic and Sports Physical Therapy, vol. 8(8), pp. 409-416, 1987).

A second, somewhat harsher criticism of the controlled Australian research would be that the stretches were completed without a thorough pre-stretching warm-up. Only four minutes of jogging and side-stepping were completed during the whole stretching regime, which meant that the first few stretches were performed with essentially no warm-up at all; warm-up is widely believed to make muscles less viscous and less resistant to elongation, thus lowering the possibility that the stretching activity itself could be somewhat damaging. Thirdly (but not finally), the stretches were carried out before training sessions took place, not after. There has been both anecdotal and research evidence which suggests that stretching is most properly placed at the ends of workouts, instead of the beginnings.

So is stretching better after workouts?
In fact, in a study carried out with 1543 runners who participated in the Honolulu Marathon, exercise physiologist David Lally, PhD. was able to link stretching before workouts with a higher risk of sustaining injury ('New Study Links Stretching with Higher Injury Rates,' Running Research News, vol. 10(3), pp. 5-6, 1994).

In Lally's survey, 47 per cent of all male runners who stretched regularly were injured during a one-year period, while only 33 per cent of male non-stretchers were hurt, a statistically significant difference (an injury was defined as a problem severe enough to disrupt normal training for at least five days). Lally's work was a cohort affair, so one might argue that those individuals who decided to stretch were also the ones who suffered from the most muscle tightness - and that this tightness caused more injuries, not the stretching. However, this relationship did not apply to female marathoners; in the fairer sex, stretchers and non-stretchers were injured at the same rate. The linkage also did not work for Oriental runners of either sex (the Honolulu Marathon is popular with Japanese endurance athletes); only white men who stretched were particularly susceptible to injuries (the popular film 'White Men Can't Stretch' hit cinemas shortly after Lally's work was published). The mechanism underlying these observations is unknown, although if the white-male-marathoner group contained a disproportionate number of 'Type-A' personalities who were rather impatient while carrying out their stretching (i.e., too quick to force their leg muscles into a stretched-out position), one would expect them to be prone to injury. Research clearly shows that a muscle suffers greater peak tension and is forced to absorb more energy as the rate at which it elongates increases ('Viscoelastic Properties of Muscle-Tendon Units,' The American Journal of Sports Medicine, Vol. 18(3), pp. 300-309, 1990).

An adept researcher, Lally was able to control for the possibility that those individuals who had been injured before his study began had taken up stretching as a prophylactic measure (this somewhat answers the concern that stretchers might have been as tight as fiddle strings; if they were really excessively taut, they would surely have had a recent history of injury and would have been excluded from Lally's analysis). If the stretchers had indeed been recovering 'wrecks', Lally's findings would have been highly biased (one of the best predictors of injury in endurance athletes is a past history of injury). When Lally threw the males with previous injuries out of his study groups, things still looked bad for the stretchers, who had a 33-per cent greater risk of injury, compared to non-stretching runners. The stretched runners did not run more miles than the non-stretched individuals, so higher mileage was not a possible explanation for the stretching-injury phenomenon.

[mtex]

What Lally himself thought
In an interview which followed the presentation of his paper at the 1994 Meeting of the American College of Sports Medicine, Lally reasoned: 'I don't know why stretching is associated with a higher risk of injury, or why the relationship is only true for white males. But there's certainly no a priori reason why stretching should limit injury risk. After all, most running injuries are caused by overuse, and stretching your muscles before workouts is not going to prevent you from overusing them.'
That is a very strong point. Stretching's role in preventing injury may be 'swamped' by the major effects of training quantity and quality - and the fitness, strength, and coordination of the athletes undertaking the training. However, before we leave Lally and his research we should mention that when he broke his data down even further, an extremely interesting nugget of information emerged: Those runners who stretched before training sessions had higher rates of injury, compared to runners who didn't stretch. However, athletes who stretched after their workouts actually had lower frequencies of injury.

When you think about stretching's true relationship to exercise, this latter finding makes sense. Although it's popular to position stretching before the actual beginning of a workout, there's actually little resemblance between the act of slowly and statically stretching a muscle (the most favoured way to stretch) and the very rapid elongations and shortenings (contractions) which muscles undergo during a workout or competition. To put it another way, stretching doesn't represent specific preparation for a real-live training session or race. In a typical stretch, a muscle is elongated and then held in a static, protracted position; its lengthening is pretty much independent of what other muscles in the leg, arm, or trunk are doing. During activity, in contrast, the muscle lengthens briefly, contracts quickly, elongates, contracts, etc., all the while coordinating its movements with other muscle groups in the involved part of the body. One could argue that a stretch increases range of motion at the joint over which the stretched muscle crosses (research has after all linked stretching with improved flexibility) and that this should facilitate movement during the ensuing training session or competition, but there is sparse evidence to suggest that stretching accomplishes this more effectively than a good warm-up (more on this in a moment).

Wanted: a follow-up to Lally
While the act of stretching bears little resemblance to what is to follow during a workout or race, that is not the case after a training session or competition are over. Athletes' muscles are often fatigued and non-resilient after a strenuous training session or workout ends. At that point, stretching is a fine way to transform a hypercontracted, non-elastic, fatigued, and non-responsive muscle into a relaxed collection of fibres which can then comfortably adapt to the more passive activities which follow the training session - and recover nicely before the next muscle trauma (i.e., workout) takes place.

Unfortunately, no one in the scientific community has picked up Lally's torch and taken a closer look at the finding that stretching may be better after a workout than before. However, a pre-Lally study carried out in 1986 does shed some light on the issue. In that investigation, researchers at Auburn University followed 51 students who were engaged in a jogging program ('Evaluation of Warm-Up for Improvement in Flexibility,' The American Journal of Sports Medicine, vol. 14(4), pp. 316-319, 1986). Prior to jogging, one group of students completed 15 minutes of stretching routines designed to unkink the shoulders, low back, hamstrings, and calf muscles (Achilles-tendon complex). The second group of joggers carried out the same routine - but only after a five-minute warm-up jog was completed.

Exercise - and then stretch?
After nine weeks, individuals who jogged before they stretched possessed significantly greater ankle flexibility, compared to the group which stretched without prior jogging. In fact, the average flexibility gain at the ankle was more than twice as great (in degrees) for the jog-stretchers, compared with the stretch-only individuals (no injury rates were assessed in this study; it was simply assumed that greater flexibility was a good thing). This Auburn work suggests that stretching is more effective - in terms of promoting flexibility - if it is preceded by exercise, instead of preceding exercise (at least at the ankle joint).

Those last six words - 'at least at the ankle joint' - actually turn out to be quite important, because in the Auburn study individuals who stretched without a pre-stretch warm-up actually achieved much better low-back flexibility, compared to those pre-stretch joggers. In fact, the people who jogged and then stretched their low-back muscles were unable to improve their low-back looseness at all!

Enhancements in hamstring flexibility were equal between the groups, but jogging and then stretching seemed to be superior to just stretching at making shoulder muscles more pliant; the jog-stretch plan increased shoulder range of motion about 60-per cent more than the simple stretching procedure. This leaves us with the prospect that pre-stretch exercise may be especially beneficial for some - but not all - muscle groups.

Better than static stretches
On a personal level (warning - anecdotal information is about to follow), I have noticed that a thorough warm-up which features a variety of dynamic activities is usually much more effective than a routine warm-up which contains traditional, static stretches. By 'effective', I mean that the varied warm-up is better at promoting flexibility and getting endurance athletes really ready to perform at their best during strenuous workouts or races, compared to the classic combo of easy exercise and static stretching. This 'special' warm-up does much more than just elevate heart rate; it is also a small-scale strength workout in its own right, and it fully prepares an athlete's nervous system to control the musculoskeletal system more efficiently during subsequent exercise. The warm-up looks complicated at first, but after a couple of times it will become routine and fun to carry out (although you may get some strange looks from other athletes and passers-by). And yes - this warm-up does enhance flexibility, just as traditional stretching would. Don't forget that each time your foot hits the ground as you run your hamstrings, quads, and calf muscles are stretched as your hip, knee, and ankle joints undergo flexion, respectively, to cushion your impact with the ground and prepare for the leg straightening associated with toe-off.



Many of the exercises in the special warm-up are dynamic enough to exaggerate these repeated stretches, yet they are not so explosive as to increase the risk of injury. You usually end the special warm-up looser and more ready to exercise than you would be if you had completed a classic warm-up with traditional stretches (I would argue - again anecdotally - that this warm-up specifically enhances ACTIVE range of motion (ROM) more effectively than static stretching, and that active ROM is certainly more important than passive ROM - both from performance and injury-prevention standpoints - during workouts and races).

Here's how the warm-up works (the overall sequencing of activity and many of the specific routines were developed by the strength-and-conditioning specialist Walt Reynolds:

The special warm-up
1. Jog, cycle, or swim easily for 10 minutes to loosen up.
2. Walk quickly on your toes with your toes pointed straight ahead for about 20 metres, getting as high up on your toes as you possibly can. Your legs should be relatively straight as you do this, and you should take fairly small steps.
Then, cover another 20 metres high up on your toes, but with your toes pointed outward about 45 degrees or so. Your legs should rotate outward from the hips when you perform this movement; don't merely turn each foot at the ankle. Finally, quickly walk another 20 metres high on your toes, but with your toes pointed inward. As you do so, rotate your legs inward at the hips, not just the ankles. Repeat each of these activities (toes pointed ahead for 20 metres, toes pointed out for 20 metres, toes pointed in for 20 metres) one more time before going on to the next exercise.
3. Walk on your heels with your toes pointed straight ahead for about 20 metres, getting as high up on your heels as you possibly can. Your legs should be relatively straight as you do this, and you should - at least initially - take fairly small steps.
Then, simply do what you did with the toe walks, walking 20 metres on your heels with toes pointed outward and then 20 metres on heels with toes pointed inward. Repeat each of the heel walks (toes straight ahead, toes pointed outward, toes in) once more.
4. Next, skip for about 20 metres, landing in the mid-foot area with each contact with the ground, and with toes pointed straight ahead. Then, do the same, but with toes pointed out for 20 metres, and then with toes pointed in for 20 metres.
5. Repeat step 4, but this time skip on your toes.
6. Complete four bouts of 'high-knee running'. To do this, begin running with very quick, short steps. Every third step, lift your alternate knee as high as you can in a very explosive manner. For example, let's say you start the high-knee running by hitting the ground with your right foot, then your left, and then your right. As soon as your right foot hits the ground the second time (the third step of the sequence), accelerate your left knee upward toward your chest as quickly as possible. Once it reaches its limit of upward movement, bring your left foot back to the ground quickly. As your left foot hits the ground, count three more steps (left-right-left), and with this second left in the new three-step sequence bring your right knee up as explosively as you can. Continue in this manner for about 30 seconds, rest for 15 seconds, and then repeat three more times.

Rhythm and dorsiflexion
7. Next, carry out some 'rhythm bounding.' By bounding, I don't mean progressing forward with extra-long strides; rather, you should jog along with very springy, short steps, landing on the mid-foot area with each contact and springing upward after impact. As you rhythm bound, your ankles should act like coiled springs, compressing slightly as you make your mid-foot landing and then recoiling quickly - causing you to bound upward and forward. Move along for one minute with quick, little spring-like strides, alternating right and left feet as you would during regular running. After this minute is completed, jog in your regular manner for about 10 seconds, and then rhythm bound for about 20 metres, alternating three consecutive spring-like contacts with your right foot with three contacts with the left (e.g., 3 hops on your right foot and then 3 hops on your left, 3 more on your right, etc., until you have travelled about 20 metres). Jog in your usual manner for 10 seconds, and then hop along for 20 metres on your right foot only, before shifting over to 20 metres on the left foot alone (make certain that you land in the mid-foot area with each ground contact). As you become stronger and more skilled, you can increase the length, amplitude (vertical height), and quickness of each bound (hop).

8. After the rhythm bounding is completed, move right into some 'dorsiflexion bounces'. To do these, simply begin jumping vertically and repetitively to a moderate height, landing in the mid-foot area with both feet and then springing upward quickly after each contact with the ground. The interesting part of this exercise is that you should 'dorsiflex' your ankles - pulling your toes toward your shins - on each ascent, before you begin falling back toward terra firma (you should 'plantar flex' your ankles slightly, e.g., point your toes, just before making contact with the ground). Complete 10 dorsiflexion bounces, rest for 10 seconds, and then carry out 10 more. As your strength and coordination improve, you can do this exercise on one foot at a time.

Now on to bouncing
9. Then, do some 'rhythm bouncing.' Rhythm bouncing is pretty easy - it merely involves jumping around, but what jumping! You should start with 10 jumps in place at a moderately fast speed, with medium height (don't pretend you are trying to 'dunk' a basketball), and with maximal motion at the ankles - but very little flexion and extension at the knees and hips. After resting for a few seconds, change the amplitude (height) of your jumps to less than an inch, and complete 20 jumps as fast as you possibly can (pretend that your feet are hitting a hotplate, so that you must minimize your contact time with the ground). Again, almost all of the action should take place at your ankles, not at your knees and hips.

So far, all of the rhythm bounces have been carried out in place, so make things interesting by jumping forward and then backward as quickly as possible (the length of these jumps should be moderate - you are not trying to set an Olympic record for the long jump). After you have made 20 contacts (each time your feet strike the ground is one contact), rest for a few seconds and then jump from side to side for 20 contacts. Rest again briefly, and then jump in a direction which is about 45 degrees from straight ahead, alternating directions (first toward the right, then to the left) for 20 contacts. The length of these jumps is moderate; you are attempting to achieve quickness, not extraordinary distance. A key point: get your propulsive force from your ankles, not from your knees and hips! As you gain strength and coordination, you will carry out each type of bouncing on one foot.

10. Jog easily for a minute or so, and then complete two 200-metre 'strides' at a pace which feels close to maximal (jog easily for 30 seconds between strides). Finally, jog lightly for one more minute, and then proceed to the main portion of your workout - or start your competition.

Please make sure that all of the bouncing, bounding, and skipping in the special warm-up is completed on a 'forgiving' surface (grass, soft dirt, carpet, or resilient gym floor, etc.). Avoid concrete and tarmac. If you carry out the special warm-up several times a week, you will become more functionally flexible and resilient - and you'll be much more ready to undertake your workout or race, compared to the person who has just jogged around a bit and stretched statically.

So what's the bottom line?
There's little scientific support for the idea that regular pre-workout stretching reduces the risk of injury during training; this is probably due to the fact that stretching's role in injury prevention is dwarfed by the effects of training quality and quantity - and the fitness, strength, coordination, and natural flexibility of the athletes undertaking the training. It's doubtful that stretching prepares athletes more effectively for exercise than a dynamic warm-up, and in fact there is some evidence (from Lally's work with marathon runners) to suggest that stretching is an ideal post-exercise activity, rather than the perfect exercise antecedent. Reinforcing the notion that stretching is an important, post-workout recovery activity, research has shown that stretching can stimulate the transport of amino acids into muscle cells, accelerate protein synthesis inside the cells, and inhibit protein degradation rates ('Stretch and Skeletal Myotube Growth: What Is the Physical to Biochemical Linkage?', in Frontiers of Exercise Biology, K. Borer, D. Edington, and T. White, eds., Human Kinetics Publishers, pp. 71-84, 1983). These latter effects mean that stretching should foster muscle repair, and they might represent the mechanism underlying Lally's finding that athletes who stretch after workouts are hurt less often. We may yet see a randomized, controlled scientific study linking stretching with reduced rates of injury, but it's likely that this study will involve post-, not pre-workout stretching.

Owen Anderson

[biker]

but what if i can't touch my toes, should i stretch..does anybody do yoga or anything like that, the shit looks weird but does it work?- thanks for the post, some good info in there

[Spook]

Stretching has its place in life. You can overdo it and I've seen people go way past parallel hoping the weights stretching the pecs to force the body to release IGF-1 only ends up feeling this "RRRIIIIIPPPP" in the muscle. Sometimes they strain the muscle, pull the muscle and one guy I new a few years ago ended up having to have the muscle surgically reattached. Now, if only Ken Griffey Jr would go out on the field and stretch with the rest of the team, he may not have so many pulled hamstrings and sprains. Flexibility is a good thing, but you can overdo it too.

[mac83]

i also see some people stretch too hard b4 they're warmed up. i like stretching best when done between sets. if u wanna get a stretch to begin with do a lighter warm up set instead