Musculoskeletal Outcomes from Chronic High-Speed High-Impact Resistive Exercise

Subjects (n=13) did 30 workouts with their left leg on an Inertial Exercise Trainer (IET), while their right leg served as an untreated control. Before and after the 30 workouts, they underwent isokinetic strength tests (knee and ankle extensors of both legs) whose peak torque (PT), time to PT (TTPT), and rate of torque development (RTD) values were each analyzed with 2(leg)×2(time)×3(velocity) analysis of variances (ANOVAs), with repeated measures per independent variable. Peak force (PF) and total work (TW) data were measured from each IET workout, and they represent time course strength changes produced by our exercise intervention. PF and TW values for the three IET exercises that comprised each workout were each analyzed with one-way ANOVAs with time as the independent variable. Results included significant ankle and knee extensor PT increases, whereby the left leg achieved higher values at posttesting, but there were no significant TTPT changes and a time effect for ankle extensor RTD. Our data show that PF and TW each had significant increases over time, with the latter exhibiting greater gains over the 30-workout intervention. Our results imply that the IET yields strength gains over time comparable to standard resistive exercise hardware.