The influence of two static stretching protocols with different intensities on concentric knee extension strength

BACKGROUND: Pre-exercise stretching is a commonly used practice by many competitive and recreational athletes. However, the effects of stretching on muscle performance are still incongruous. Furthermore, there is conflicting evidence regarding the intensity of stretching and the effect it has on muscular strength. OBJECTIVE: To investigate the effects of two different intensity levels of passive static stretching protocols on concentric knee extension strength. METHODS: Twenty-two male recreational athletes involved in regular resistance training programs were evaluated using a randomized design. Subjects performed an isokinetic test of the knee extensors following either maximal intensity static stretching, submaximal intensity static stretching, or no stretching. RESULTS: The only significant difference in the peak moment, amounting to 10.5%, was noted between maximal intensity stretching and no stretching. CONCLUSION: Maximal intensity stretching of the quadriceps may adversely affect the acute concentric moment production capacity of these muscles.