Last issue I looked at the scientific evidence for saying that stretching, either before or after exercise, lowers the risk of injury. As a follow-up to that, and on an anecdotal level, 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 minimise your contact time with the ground). Again, almost all of the action should take place at your ankles, not at your knees and hips.
'A key point: get your propulsive force from your ankles, not from 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 flexibile 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.