STRETCHING AND WARM-UPS
by Dave Sears
Editor of Muscles in Minutes
Many trainees wonder how important stretching and warming-up is prior to (or after) a workout. Recent research sheds some light on that subject with regards to two different variables:
1. assistance in reducing injuries
2. reduction in muscle soreness
A third, and more important variable we "wish" they tested was:
3. contribution to performance (does it improve performance?)
Some of you may have read the full report in the August, 2002 issue of the British Medical Journal, detailing seven studies (including 2 on army recruits undergoing military training) testing this very thing. While the results are not overwhelmingly conclusive, they certainly show congruity of findings.
I'll spare you the details and share a few of the summaries: "clear evidence from five studies… …stretching before or after exercising has no effect on delayed onset muscle soreness." And "Two further studies on army recruits… … strongly suggest that muscle stretching before exercising does not produce meaningful reductions in the risk of injury."
More specifically with regards to reducing muscle soreness… "The results of five studies imply that stretching reduces soreness in the 72 hours after exercising by, on average, less than 2 mm on a 100 mm scale. Most athletes will consider effects of this magnitude too small to make stretching to prevent later muscle soreness worthwhile." So while researchers found a small reduction, it was not as significant as many trainers believe.
The results on injuries (that we're normally told would be prevented by stretching) were similar: "The [findings] from two studies [military recruits with high incidence of injuries] was that stretching decreased the risk of injury… …a statistically non-significant [percentage]." It was concluded that: "the average subject would need to stretch for 23 years to prevent one injury." And further suggested that since: "Most athletes are exposed to lower risks of injury, the absolute risk reduction for most athletes is likely to be smaller still." Have any of you heard the point of view that you can "over-stretch" a muscle group to the point that you will exacerbate your risk of injury?
Do keep their final discussion point in mind: "Although these data imply that the muscle stretching protocol used in these studies does not appreciably reduce risk of injury in army recruits undergoing military training, it is not possible to rule out with certainty a clinically worthwhile effect of other stretch protocols on risk of injury in other populations. It would be particularly interesting to determine if more prolonged stretching carried out by recreational athletes over many months or years can produce meaningful reductions in risk of injury."
And while these studies did not draw conclusions about the effect of stretching on athletic performance, we should question it ourselves. While we're at it, how about "warm-ups" as opposed to stretching (since they are certainly not the same thing)? While I haven't received a lot of inquiries about stretching, I have about the relevance of warm-ups.
I recall reading that one trainee was excited to see his Time Under Load (TUL) increase (a high TUL, I should point out) in the squat, when he performed multiple sets (as a warm-up) beforehand. Did the warm-ups really cause the "working set" to create a greater demand on the muscles (thereby increasing the benefit of the set) or did they simply allow the set to be carried on longer (without added benefit)? In other words, did the individual actually stimulate more fibers or did the warm-up simply allow better performance (but otherwise do nothing in terms of cause and effect)? We have to be deliberate in discerning between "performance enhancers" and actual improvement in muscular stimulation. As bodybuilders (not weightlifters), we are not interested in set performance – we’re interested in results! If you want to test the effect a warm-up has on exercise performance, please do, but do it critically.
I personally only do as much (little) exercise as necessary prior to an intense set. How much is that? Not much at all. Most trainees are surprised to hear that I do not perform a traditional warm-up set prior to the working set. I "may" occasionally do 4-6 reps with 1/2 the final weight, but that's only to ensure that I'm confident that my muscles are prepared to accomplish the task yet to come, not to "warm-up" the muscles. To effect increased blood flow prior to a hard, working set, I depend almost entirely upon slow and controlled joint rotations - elbows, shoulders, knees, hips, and neck. I only do those few light reps (when they're done at all) as a final check before proceeding.
Why don't I do more? Because I've never seen evidence to support it, and, as Mike Mentzer said many times: "Any amount of exercise beyond what is minimally necessary is a negative factor!" To quote Mike in Muscles in Minutes: "Make sure that you spend some time warming the muscles to be worked. However, it is not necessary to stretch the muscles, perform aerobic work, or engage in any more exercise than is minimally required to limber up and increase the blood flow to the specific muscles you're working that day."
Do not take what I (or Mike) say as gospel - test for yourself. And when you do, make sure your results are evaluated by the same method / instrument (e.g., Don't have your body-fat checked by using hydrostatic weighing one month, then try skin-fold calipers the next, and finally use an electrical impedance tester. What would these three tests tell you about your progress? Absolutely nothing!) Make sure to measure and record your TUL in addition to weight used and reps performed to analyze results from workout to workout. Don't leave your progress to chance.
If stretching and warm-ups do not prevent soreness and injuries (as we've all been told for so many years), what other "common knowledge" should we challenge?