The association between negative muscle work and pedaling rate

Area of Science:

• Sports Science
• Biomechanics
• Exercise Physiology

Background:

• Understanding muscular forces during cycling is crucial for optimizing performance.
• Negative muscular crank torque, or braking torque, plays a role in the complex dynamics of pedaling.
• Previous research has explored pedaling mechanics, but the specific quantification of negative torque across various cadences requires further investigation.

Purpose of the Study:

• To quantify negative muscular crank torque in competitive cyclists across a range of pedaling rates.
• To test the hypothesis that negative torque increases at higher pedaling rates due to muscle activation dynamics and control demands.
• To determine the correlation between negative muscular crank torque and pedaling rate.

Main Methods:

• Utilized a pedal force decomposition approach to analyze crank torque.
• Collected data from competitive cyclists at pedaling rates of 60, 75, 90, 105, and 120 revolutions per minute (rpm).
• Maintained a constant power output of 260 W during data collection.

Main Results:

• A significant effect of pedaling rate on average negative muscular crank torque was observed (p < 0.05).
• No negative torque was generated at 60 rpm, with negligible amounts at 75 and 90 rpm.
• Substantial negative muscular crank torque was generated at 105 and 120 rpm, increasing with higher cadences.

Conclusions:

• Negative muscular crank torque is significantly correlated with pedaling rate in competitive cyclists.
• The ability of working muscles to accelerate the crank diminishes at higher pedaling rates.
• Findings suggest that optimal cycling efficiency may be linked to the pedaling rates cyclists naturally prefer (around 90 rpm).