The effects of velocity specific isokinetic training on strength, hypertrophy, and cross education

Abstract

This study examined the effects of six weeks of velocity specific isokinetic training on peak torque (PT), and the estimated cross-sectional area of the upper arm (AG) in the trained. Thirty volunteers (M=15, F=15) were randomly assigned to an experimental, slow velocity group (S), 60 degrees-per-second (n=9; 25.4±..6.5yr), a fast velocity group (F), 450 degrees-per-second (n=ll, 23.7 ±..S.4yr), or control group (C) (n=10, 26 ± 3.2yr). One limb was randomly selected for isokinetic training (3 d/wk-elbow flexion) using a Biodex System 2 isokinetic dynamometer. The contralateral limb served as a control and as the basis for measurements measure of cross education (CE). Both experimental conditions (S) and (F) were assigned equal training workloads, calcu1ated from an isokinetic pre-test. Pre- and post-tests (PT) were recorded for both limbs at the training velocities of 60 and 450 degrees-per-second, as well as the velocity of 210 degrees-per-second. Pre and post-test (AG's) were measured on the training limb. The (S) condition was significantly different in strength gains from the control at 60 degrees-per-second, but not different from the fast velocity group in the trained limb. The (F) condition was significantly different in strength gains from the control at 450 degrees-per-second, but not different from the slow velocity group in the the trained limb. The conditions were not significantly different from each other in the trained limb at the test velocity of 210 degrees-per-second. The three conditions significantly different from each at the test velocity of 60 degrees-per-second in the trained limb. The conditions did not differ in strength at velocities of 210 and 450 degrees-per-second in the trained limb. The conditions did not differ in the cross-sectional area of the upper arm in the trained limb. The (S) and (F) training conditions improved (PT) by 12.36% and 18.84% at their respective training velocities of 60 and 450 degrees-per-second. These improvements were significantly (p<.05) larger than (C). The (S) and (F) training conditions also increased (PT) by 11.56% and 11.24% at the non-training velocity of 210 degrees-per-second (p<.05). Significant 10.77% (p<.05) improvement in (AG) was recorded in the (S) condition. No changes in (PT) were recorded in the contralateral limb within the three conditions. These data support the concept of limited (S) and (F) hi-directional (PT) overflow and (S) velocity hypertrophy enhancement. The presence of cross education (CE) was not supported by this investigation.