Stretching to Prevent Injuries from Starting
IronMan Magazine ..
Several recent studies, many of which have been reported in this column, assert that stretching before lifting weights leads to a loss of strength during the weight training.
The main purpose of stretching in that situation is to warm up the muscles and increase flexibility, but according to recent studies, increased flexibility is not desirable when
strength and muscular performance during training are the goals. Even the necessity of stretching to prevent injury is debatable, with several studies showing no protection.
At first glance it appears that stretching should be restricted to those engaged in nothing more strenuous than aerobics. Don't confuse that with warming up, however. No one argues
that a warmup increases muscular efficiency. The suggested warmup would be lighter movements of the same activity you plan to engage in. But a closer look at the studies reveals
some notable flaws.
For example, many of them featured extended stretching sessions, lasting anihere from 100 seconds to 30 minutes, usually with static stretches. A static stretch involves holding
a position for 10 to 30 seconds. In the real world few bodybuilders will stretch for 30 minutes before training. The usual practice is to either do a short stretch just before you
perform an exercise or to stretch between sets of the exercise. The antistretching studies also found that most of the strength loss lasted for only 30 seconds after the stretch
was completed. Other studies found that strength returned immediately after the stretch ended, indicating that muscle strength dropped only during the actual stretch.
That makes sense, as stretching does lessen muscle tension, which is involved in strength production. If that's the case, stretching a muscle for 30 seconds may have little or no
effect on subsequent strength performance. A recent study examined the effects of 30 seconds of static stretching and dynamic stretching on muscle strength and power on the leg
extension.1 Eight healthy male college students participated. All of them were active recreationally and had a history of weight training, but none of them had stretched or lifted
weights just prior to the study. Dynamic stretching involves flexing a muscle that's antagonistic to the target muscle quickly and strongly right before stretching the target
muscle. For example, if you wanted to stretch your triceps muscle of the upper arm, you would first contract your biceps muscle (antagonistic to the triceps), then immediately
stretch your triceps. The subjects stretched in that manner five times, slowly at first, then 10 times as quickly and powerfully as possible without bouncing. That's why it's called
dynamic. The subjects also did static stretches, - holding the position for 30 seconds.
The results: Doing static stretches for no more than 30 seconds did not lessen muscle power or strength. Those who did longer static stretches did show some loss of power. It was most
evident in those who had the most power on leg extensions before doing the stretches. The implication is that static stretching for 30 seconds would likely have an adverse effect on
more experienced or stronger bodybuilders. In contrast, not only did dynamic stretching not adversely affect strength or power, but it actually increased both when done before the
leg extensions. How it does that isn't clear, but one theory is that dynamic stretching increases intramuscular temperature, making the muscle more efficient. Or, possibly, the
contraction of the antagonistic muscle just prior to stretching the target muscle allows some type of neurological force transmission to increase in the target. The implications for
bodybuilding purposes are that it's a good idea to engage in dynamic stretching just before you perform an exercise; however, static stretching should be avoided, especially by more
advanced and stronger bodybuilders, since it induces a muscle relaxation effect that can have a negative effect on exercise performance
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