RESUMEN
Athletes may benefit from isokinetic training (IK) to improve strength and jump performance. Previous studies comparing IK methods to isotonic resistance training (IT) have utilized high-repetition protocols and a Dynamometer, which are usually reserved for laboratory or rehabilitation settings. This study compared effects of IK and IT using ≤ 6 repetitions on strength and jump performance in 50 male, team-sport athletes (ages 18-35) during COVID-19 lockdown using the commercially-available TechnoGym BioCircuit Dynamometer. This 4-group randomized parallel study assessed the effects of an 8-week isokinetic at 80°/s (IK80; n = 16) and 25°/s (IK25; n = 12) or isotonic training program (IT; n = 15) compared to a control group (CG; n = 7) on anthropometric measurements, peak torque at 80°/s (PT80) and 25°/s (PT25), one-repetition maximum (1-RM) leg extension, and countermovement (CMJ) and squat jump height (SJ). Anthropomorphic data showed minimal differences between groups post-intervention. Strength increased in IT, and IK25 compared to CG, with no difference between intervention groups. SJ increased in all groups compared to the control group, with differences between groups. Counter movement jump (CMJ) improved only in IT and IK80 with no between-group difference. These results do support the hypothesis that low-repetition IK and IT can be used to effectively improve strength and jump performance in athletic populations. However, the efficacy of IK on CMJ depends on training velocity and repetition range, with a higher velocity training protocol (80°/s) being more effective for jump performance and lower speeds potentially more useful for improving maximal strength (25°/s).
