by Thomas Kurz
An article in the August 2006 issue of Journal of Strength and Conditioning Research describes a study comparing the effect of a dynamic warm-up with the effect of a static stretching warm-up on three tests of power and agility (McMillian et al. 2006). The study proved, as could be expected, that the dynamic warm-up resulted in better test performances than either static stretching or no warm-up.
Now about the specifics of the study: Thirty cadets of the U.S. Military Academy (14 women and 16 men) performed a T-shuttle run, an underhand medicine ball throw for distance, and a five-step jump after a dynamic warm-up or a static stretching warm-up or no warm-up. Performance scores on all three tests were better after the dynamic warm-up than after the static stretching or no warm-up. So nothing new—these results are as expected by readers of my book Stretching Scientifically or any intelligent student of exercise physiology.
Further, for two tests (the medicine ball throw and the shuttle run) there were no significant differences between performances after the static stretching and after no warm-up. For the five-step jump, however, the static stretching was better than no warm-up (but not better than the dynamic warm-up). That aroused my curiosity. After reading the researchers’ description of their static stretches, I think I know why their subjects did better on the five-step jump after static stretching than after no warm-up.
Except for the calf stretch, techniques of relevant static stretches (rear lunge and reach, hamstring stretch, quadriceps stretch, posterior hip stretch) were such as to make acute (intense) stretching of the targeted muscles unlikely. Only in the calf stretch were the subjects likely to intensely stretch their calves.
All tests were done at 06:00 (6 a.m.), with no prior exercise, so those mild static stretches warmed up somewhat the muscles most stressed in the five-step jump and increased range of motion in the hip joints. This helped the subjects do better on this test than when they had no warm-up at all.
Performance on other tests (T-shuttle run and medicine ball throw) was not improved by static stretching as compared with no warm-up. I guess this was because (a) most of the static stretches were not relevant to these tasks and (b) those that were relevant (turn and reach, trunk flexion/extension stretch, overhead arm pull) were done in positions so easy to hold that they did not warm up the targeted muscles even as little as needed to do better than after no warm-up. (Readers who want to read a description of all the stretches, as well as of the dynamic warm-up and the tests, should obtain the original article—McMillian, D. J., J .H. Moore, B. S. Hatler, and D. C. Taylor. 2006. Dynamic vs. static-stretching warm-up: The effect on power and agility performance. Journal of Strength and Conditioning Research vol. 20, no. 3, pp. 492–9.)
But there is more to that article—and it’s not good. I didn’t know whether to laugh out loud or just smirk when I read it. I will quote from that article so you can see why I felt that way.
Here are the quotes:
“United States Army Physical Fitness School (APFS) developed a Dynamic Warm-Up (DWU) for individuals and military units. . . . This DWU was used [for 9 weeks in 2003] before each exercise session as a part of an intervention to decrease injuries and improve physical performance among soldiers in a basic training battalion. . . . Static stretching, a prominent feature of the warm-up for generations of soldiers, was not included.”
Further: “[As an effect of this DWU] injury rates over the 9-week training period were significantly decreased compared with both a control battalion and historic trends. Performance on physical fitness testing generally was improved.”
No wonder—if the previous warm-up routine was designed and conducted by people dull enough to put static stretching in it!
But the real beauty is that this one DWU routine was used unchanged for every exercise session during 9 weeks of army training—no matter what the task of the session. I am so glad I was not trained by experts from United States Army Physical Fitness School (APFS).
Here is a quote from page 60 in Science of Sports Training:
“A good [instructor] will rarely repeat the same sequence of warm-up exercises in different workouts. The tasks of the workouts change and the warm-up has to be built of the exercises that best prepare the athletes for the current task. Usually the task-specific part of the warm-up lasts five to ten minutes. A specific warm-up should blend with the main part of the workout. If several tasks have to be realized during a workout (for example, gymnastic techniques on different apparatus), then each task may be preceded by its own specific short warm-up.”
This applies to military exercise sessions too. After all, not every exercise session is the same, even in the military. The content of sessions changes as recruits become conditioned and skills change.
It is foolish to push trainees’ limits in all tasks in one session and expect them to improve, so different tasks need to be covered in separate exercise sessions. If recruits have to run obstacle courses, they are not likely to learn combat skills in the same session. If recruits have to practice swimming, they are not likely to train for a 2-mile run test in the same session.
Various systems affecting the functional abilities of the body recover after exercise, and thus can reach supercompensation, in different lengths of time. This allows a person to work out daily or even several times a day, without overtraining, provided that the content of each consecutive workout stresses the system that has sufficiently recovered and does not adversely affect the recovery of other systems. The content of each workout depends on the previous workouts, on the workouts that will follow it, and on the type and amount of rest.
More information on designing warm-ups for various types of workouts and for competitions can be found in the subchapter “Structure of a Workout” on pages 59–64 of Science of Sports Training.
If you have any questions on training you can post them at Stadion’s Sports and Martial Arts Training Discussion Forum.
To learn more about rational warm-up, read Stadion books Stretching Scientifically and Science of Sports Training: How to Plan and Control Training for Peak Performance. Get them now and have all of the info—not just the crumbs! Order now!
In the next article you will learn about the main part of a workout.
If you have any questions on training you can post them at Stadion’s Sports and Martial Arts Training Discussion Forum