Relationship between individual hip extensor muscle size and sprint running performance: sprint phase dependence

Area of Science:

• Biomechanics
• Sports Science
• Human Physiology

Background:

• Hip extensor muscle size is considered crucial for sprint running performance.
• Existing research presents inconsistent findings regarding this relationship.
• The influence of hip extensor muscle size may differ across distinct sprint phases.

Purpose of the Study:

• To investigate the hypothesis that hip extensor muscle size association with sprint performance varies by sprint phase.
• To differentiate the roles of specific hip extensor muscles (semimembranosus, semitendinosus) in different sprint phases.

Main Methods:

• Magnetic resonance imaging (MRI) was used to measure individual hip extensor muscle volumes in 26 male sprinters.
• Sprint velocities were recorded at 10-m intervals during a 100-m maximal-effort sprint.
• Sprint phases (early-acceleration, maximal-velocity, deceleration) were determined based on individual sprint velocities.

Main Results:

• Semimembranosus muscle volume relative to body mass showed a positive correlation with sprint velocity specifically during the early-acceleration phase (0-10 m).
• Semitendinosus muscle volume relative to body mass correlated positively with sprint velocities during both the maximal-velocity and deceleration (90-100 m) phases.
• These findings indicate a phase-dependent relationship between hip extensor muscle size and sprint performance.

Conclusions:

• The association between hip extensor muscle size and sprint performance is not uniform but dynamic, changing across different phases of a sprint.
• Specific hip extensor muscles contribute differentially to sprint performance depending on whether the sprinter is accelerating, at maximal velocity, or decelerating.
• Understanding these phase-specific relationships can inform targeted training strategies for sprinters to optimize performance.