Maximum Sprints Elicit Higher Peak Knee Joint Power than Resistance Training Exercises

Area of Science:

• Biomechanics
• Sports Science
• Exercise Physiology

Background:

• Sprinting imposes extreme mechanical stress on knee flexors, especially hamstrings during the late swing phase.
• Coaches utilize high-intensity eccentric resistance training to enhance hamstring energy absorption.
• The equivalence of training loads to maximal sprint demands remains uncertain.

Purpose of the Study:

• To compare peak knee power in maximal sprints versus strenuous hamstring exercises.
• To determine if current resistance training replicates sprint-specific mechanical demands.

Main Methods:

• Aggregated previously published data from inverse dynamic analyses.
• Included sprints, explosive Razor Curls, decelerated Nordic Hamstring Exercise, and isokinetic hamstring tests.
• Compared peak knee power values across different activities.

Main Results:

• Maximal sprints exhibited 8-14 times greater absolute and relative peak knee power compared to analyzed hamstring exercises.
• This difference was primarily driven by 6-14 fold higher knee extension angular velocities during sprinting.
• Peak knee power during sprinting was not matched by any of the tested hamstring exercises.

Conclusions:

• Strenuous hamstring exercises, even when explosive, do not replicate the peak knee power demands of maximal sprinting.
• Current resistance training protocols may not fully prepare athletes for the high-intensity, high-velocity demands of sprinting.