Athletes are always looking for little tips and tricks that will give them an edge over their opponents. In recent posts we discussed the various ways in which athletes can take advantage of post-activation potentiation. By performing explosive movements following maximal strength training, one can expect a transient increase in output. Other research has investigated the acute performance improvements seen following HRV biofeedback. Even icing the shoulders of pitchers between innings has shown some promising effects on maintaining pitching velocity in baseball. Timed and implemented appropriately, these aforementioned methods may be worth experimenting with.
Static stretching is a bit of a buzz word lately in the strength and conditioning community. Years ago, everyone was static stretching before practice or competition. It was part of just about everyone’s warm-up and cool down routine. It’s now pretty well understood that static stretching may result in acute decrements in force production if done excessively before training or sport participation. As a result, the pendulum has swung completely in the other direction where static stretching has been stricken from pre-exercise activities for many teams. The fact of the matter however, is that static stretching has it’s place in pre-exercise routines when used appropriately.
Some new research out of Canada, published in the Journal of Strength and Conditioning Research evaluated the effects of static stretching specific muscles before vertical jump testing. Fifteen college-aged males had their vertical jumps tested at baseline, after which the subjects returned on 3 more occasions. In a randomized order, the subjects stretched their hip extensors before vertical jump testing on one occasion; stretched their hip flexors before vertical jump testing on another; and once more with no stretching for a control.
The results showed that hip flexor stretching before vertical jump testing resulted in an average of 1.75% better score while hip extensor stretching and the control condition had negative effects (-1.74% and -1.34%, respectively). The researchers also found that that increase in vertical jump from hip flexor stretching was NOT related to hip flexor compliance. In other words, though range of motion was increased from the stretching, this did not correlate with the increased vertical jump.
A potential mechanism through which hip flexor stretching may contribute to higher jumping is through reducing reciprocal inhibition. The glute muscles, which are powerful hip extensors, may have increased recruitment when the hip flexors are loosened. It would be interesting to re-create this study using EMG to assess muscle activity. Regardless of the mechanism, it appears that stretching your hip flexors before performing explosive hip extension type movements, such as a vertical jump, may transiently increase performance.
Reference:
Wakefield, C. B., & Cottrell, G. T. (2014). Changes in hip flexor passive compliance do not account for improvement in vertical jump performance following hip flexor static stretching. Journal of Strength and Conditioning Research, Ahead of print.
