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Joint-specific power production during submaximal and maximal cycling
Steven J Elmer1, Paul R Barratt, Thomas Korff
1Department of Exercise and Sport Science, University of Utah, Salt Lake City, UT 84112-0920, USA. Steve.Elmer@utah.edu
Medicine and Science in Sports and Exercise
|March 31, 2011
Summary
As cycling power increases, knee extension power decreases while knee flexion power increases, with hip extension remaining dominant. Increased leg and joint duty cycles contribute to higher maximal power output.
Area of Science:
- Biomechanics
- Exercise Physiology
- Sports Science
Background:
- Previous research indicates varying joint power dominance in submaximal (knee extension) versus maximal (hip extension) cycling.
- However, a comprehensive analysis of joint-specific power contributions across a wide spectrum of cycling intensities within a single cohort is lacking.
Purpose of the Study:
- To quantify the contribution of ankle, knee, and hip joint actions to power production across a range of net cycling powers (P(net)).
- To test the hypothesis that relative knee extension power decreases and relative knee flexion and hip extension powers increase with rising P(net).
Main Methods:
- Eleven cyclists completed submaximal and maximal cycling trials at a consistent cadence (90 rpm).
- Joint-specific powers (ankle, knee, hip) were calculated and averaged over pedal revolutions and phases (extension/flexion).
- Linear regression analyzed the relationship between relative joint powers and P(net).
Main Results:
- Absolute powers at all joints increased with P(net).
- Relative knee extension power significantly decreased (r(2)=0.88, P=0.01) while knee flexion power significantly increased (r(2)=0.98, P<0.001) as P(net) rose.
- Relative hip extension power remained constant across all tested P(net) levels.
Conclusions:
- Absolute joint powers scale with increased cycling intensity (P(net)).
- Hip extension is consistently the dominant power-producing action, irrespective of intensity.
- Knee flexion becomes a more critical contributor to power at higher intensities.
- Enhanced joint and whole-leg duty cycles are a key strategy for achieving maximal cycling power.
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