Force-velocity profile in sprinting: sex effect

Area of Science:

• Biomechanics
• Human Physiology
• Sports Science

Background:

• Muscle power during sprint acceleration is crucial for athletic performance.
• Previous studies on sex differences in the force-velocity (F-v) profile often lacked appropriate scaling.
• Understanding these differences is key to optimizing training and performance.

Purpose of the Study:

• To investigate sex differences in the F-v profile using an allometric scaling model.
• To examine the influence of body mass (BM), fat-free mass (FFM), lower limb fat-free mass (FFMLL), muscle cross-sectional area (CSA), and leg length (LL) on F-v parameters.
• To determine the proportion of sex differences in the F-v profile attributable to FFM.

Main Methods:

• Thirty students (15 men, 15 women) performed three maximal 35m sprints.
• Velocity-time data were collected using radar technology.
• The F-v relationship parameters (F0, v0, Pmax) were calculated by modeling the velocity-time curve with an allometric approach.

Main Results:

• When scaled by BM and FFM, no significant sex differences were found in maximal force (F0) and maximal power output (Pmax).
• Significant sex differences persisted for Pmax scaled by FFMLL, F0 scaled by CSA, and maximal velocity (v0) scaled by LL.
• Fat-free mass accounted for 83% of the observed sex differences in the F-v profile.

Conclusions:

• Allometric scaling reveals that differences in the F-v profile between men and women are not solely explained by body size or composition.
• Factors beyond FFM, such as physiological qualitative differences, likely contribute to the observed sex-based disparities in sprint mechanics.
• Further research should explore these underlying physiological mechanisms to better understand sex-specific performance capabilities.