Joint-specific power loss after eccentric exercise.

Area of Science:

• Biomechanics
• Exercise Physiology

Background:

• Eccentric exercise is known to alter maximal power output.
• The specific impact of joint-level eccentric power absorption on subsequent concentric power production in multijoint movements remains under-investigated.

Purpose of the Study:

• To quantify ankle, knee, and hip joint power absorption during eccentric cycling (ECCcyc).
• To assess the changes in power production of these joints during subsequent maximal concentric cycling (CONcyc).
• To test the hypothesis that joints absorbing more eccentric power would show greater reductions in concentric power.

Main Methods:

• Nineteen cyclists completed maximal single-leg CONcyc trials before and 24 hours after a single-leg ECCcyc session.
• Pedal forces and limb kinematics were measured using a force-sensing pedal and an instrumented linkage system.
• Joint-specific powers were calculated via inverse dynamics, averaged over crank revolutions and movement phases.

Main Results:

• Eccentric knee extensors absorbed the most power (-185 W), followed by hip extensors (-92 W); ankle absorption was minimal (-10 W).
• Overall CONcyc power decreased by 11% at 24 hours post-ECCcyc.
• Concentric knee extension power reduced by 19%, while hip extension power remained unchanged.

Conclusions:

• Eccentric knee extension significantly impaired subsequent concentric knee extension power.
• Despite reduced knee extensor function, overall power output remained high (89% of baseline).
• Findings are relevant for activities requiring sustained multijoint performance after eccentric loading.