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Chronic stretching and voluntary muscle force.
Dain P LaRoche1, Mélanie V Lussier, Stephen J Roy
1Department of Kinesiology, University of New Hampshire, Durham, New Hampshire, USA. dain.laroche@unh.edu
Journal of Strength and Conditioning Research
|June 14, 2008
Summary
Four weeks of static or ballistic stretching had minimal impact on muscle force, power, or optimal length. Stretching after exercise is recommended for flexibility, but not before high-force activities.
Area of Science:
- Exercise Physiology
- Sports Science
- Biomechanics
Background:
- Flexibility training, including static and ballistic stretching, is commonly incorporated into exercise regimens.
- The effects of different stretching modalities on key muscle performance metrics remain a subject of investigation.
Purpose of the Study:
- To investigate the impact of 4 weeks of static or ballistic stretching on muscle force, power, and optimal length.
- To compare the effects of stretching interventions against a control group.
Main Methods:
- Twenty-nine male participants (18-60 years) were divided into static stretching, ballistic stretching, and control groups.
- Muscle performance was assessed via hip extension maximal voluntary contractions measuring peak torque (PT), rate of torque development (RTD), work (W), and PT angle (PTA).
- Testing was conducted before and after a 4-week intervention period.
Main Results:
- No statistically significant differences were observed in PT, RTD, or W between the stretching groups and the control group.
- PTA showed minimal changes across all groups, suggesting no significant muscle lengthening occurred.
- While some improvements were noted in the ballistic group for work, overall results indicated little effect of stretching on muscle strength and power.
Conclusions:
- Four weeks of static or ballistic stretching demonstrate negligible effects on muscle strength, power, and the length-tension relationship.
- Stretching did not significantly alter the optimal length of the hip extensor muscles.
- It is advised to perform stretching post-exercise for flexibility maintenance and to utilize dynamic warm-ups before activities requiring high muscle force.
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