Specificity of strength gains after 12 weeks of isokinetic eccentric training in healthy men

Although previous studies have demonstrated that skeletal muscle adaptations were specific to the types of stimuli, eccentric training studies presented controversial results concerning strength gains in eccentric, isometric and concentric tests. Therefore, the goal of this study was to evaluate torque-velocity adaptations following isokinetic eccentric training protocol using the quadriceps as a model. Twenty physically active men were randomly assigned to a control group (CG; n = 10) or to an eccentric training group (ETG; n = 10). Knee extensor torque-velocity relationship including isometric tests and isokinetic tests at 60 degrees/s, 120 degrees/s, 180 degrees/s, 240 degrees/s and 300 degrees/s in concentric and eccentric modes, were assessed before and after a 12-week period of eccentric training (3 sessions/week; 2-5 sets of 7-9 maximal repetitions per session performed at 60 degrees/s along a range of motion 90 degrees). Isokinetic eccentric training significantly increased the knee extensor torque at the training velocity (59%) and at the adjacent velocities (24% at 120 degrees/s and 29% in the isometric test). These results demonstrate the specificity of strength gains in isokinetic eccentric training in relation to contraction type and to angular velocity.