Is a joint moment-based cost function associated with preferred cycling cadence?

Area of Science:

• Biomechanics
• Sports Science
• Exercise Physiology

Background:

• Understanding preferred pedaling cadence (PC) is crucial for optimizing cycling efficiency and injury prevention.
• The relationship between joint moments and PC across different training backgrounds and power outputs requires further investigation.

Purpose of the Study:

• To determine if the cadence minimizing lower extremity net joint moments (cost function cadence) aligns with PC in cyclists and runners.
• To assess how cost function cadence and PC respond to increasing power output.
• To evaluate the generalizability of this association across varying levels of cycling experience and aerobic fitness.

Main Methods:

• Net joint moments at the hip, knee, and ankle were calculated using 2-D inverse dynamics from video and force data.
• A cost function was defined as the sum of absolute net joint moments to predict the cadence that minimized these moments.
• Subjects included experienced cyclists, well-trained runners, and less-trained noncyclists tested at various cadences and power outputs.

Main Results:

• Cost function cadence was not significantly different from PC at any power output across all groups.
• Cost function cadence increased with power output (e.g., 86 rpm at 100 W to 98 rpm at 200 W) for all participants.
• Preferred pedaling cadence showed minimal change or a slight decrease with increasing power output, diverging from the cost function cadence trend.

Conclusions:

• Minimizing net joint moments is a factor modestly associated with preferred pedaling cadence selection in cyclists and runners.
• The differing responses of cost function cadence and PC to increased power output suggest that joint moment minimization is not the sole determinant of preferred cadence.
• Findings highlight the complex interplay of factors influencing optimal pedaling technique across different athlete profiles and exercise intensities.