The maximum flywheel load for assessing flywheel performance: validation and reproducibility in the squat exercise

This workstudiedthe conceptof the maximum flywheel load (MFL) as a measure of maximum dynamic performance in the flywheel half-squat exercise. Twenty physically active participants were recruited for the study. The MFL load was calculated using anexponential mean concentric angular acceleration-moment of inertia relationship, at the point where its’ first derivative was lower to 1 unit. Construct validity was analysed by studying the association between MFL and sprint (peak velocity) and jump (countermovement jump, drop jump, and repeated jump in 30” heights, vertical stiffness, and reactive strength index) performance. The reliability of the test-retest was analysed after four and eight sessions. MFL showed moderate to very large significant associations with sprintvelocity, jump height, drop jump stiffness, and reactive strength index. Test-retest analysis revealed excellent relative (intraclass correlation coefficient = 0.91) and good absolute reliability (coefficient of variation, after four (4.2%), and after eight (3.9%) familiarization sessions).