Initial contractions of a single-load fatiguing exercise provide a valid assessment of age-related differences in peak power

The initial contractions of a single-load fatiguing exercise can determine peak power outputs, showing a strong correlation ( r = 0.962) with a comprehensive isokinetic torque-velocity assessment in young, old, and very old males and females. This approach accurately captures the age-related differences in peak power while simultaneously quantifying fatigability. Although peak power is underestimated by ∼13% compared with the torque-velocity assessment, the approach offers a practical way to evaluate two important neuromuscular outcomes in a single task.