Search This Blog

Thursday, February 18, 2010

Dynamic Stretching Proves Best For Jump Training

For many years, static stretching was recommended as superior to dynamic stretching for improvement of flexibility. Static stretching involves slowly stretching a muscle to the point of mild discomfort, then holding the position for 15 or more seconds. Dynamic stretching involves moving the body into and immediately out of the stretched position, repeating the cycle for several repetitions. However, while static stretching may be more effective than dynamic stretching for improving range of motion, static stretching performed immediately before explosive activities (e.g. jumping, sprinting) has been found to impair performance.

Experimental Procedure
A study by Hough, Ross, and Howatson, described in the Journal of Strength and Conditioning Research (vol 23, no 2, 2009, pages 507-512) compared the effects of static vs. dynamic stretching on jump performance immediately after stretching. Eleven college-age males jumped on different days after either 1) not stretching, 2) performing static stretching, or 3) performing dynamic stretching. The stretching routines both targeted the ankle extensors (calf), hip extensors (butt), hamstrings (rear thigh), hip flexors (front thigh-torso junction), and quadriceps (front thigh). On the static stretch day, someone held the subjects' limbs in each stretch position for 30 seconds. On the dynamic stretch day, the subjects moved into and out of each stretched position 5 times slowly and 5 time quickly, without bouncing. Jump testing (3 max height jumps from a self-selected bent-knee position) was performed 2 minutes after the stretching.

Experimental Results
There were significant differences in jump height between all 3 stretching conditions. After static stretching, the subjects jumped 4.2% less vertical distance than when they didn't stretch at all. However, after dynamic stretching, the subjects jumped 4.9% greater distance than when they didn't stretch. The static stretching did not decrease muscle electrical activity, so its detrimental effect may be due to reduced muscle stiffness. However, the dynamic stretching increased muscle electrical activity, which may account for its positive effect on jump performance.

Bottom Line
Performance of explosive activities like jumping and sprinting can be enhanced by dynamic stretching immediately before the activity. Yet static stretching detracts from explosive performance.

Other research has shown that the negative effect of static stretching on explosive performance is short-term. Therefore, because static stretching is effective for improving flexibility, it can safely be performed following athletic performance or exercise routines without interfering with the following day's athletic performance. This is particularly relevant to sports like gymnastics, that require great flexibility .

No comments:

Post a Comment

We welcome questions and comments.