Adaptations of short-term high-velocity isokinetic training vs. short-term plyometric training on vertical jump and isokinetic performance in physically active people

Abstract

BACKGROUND: The effect of short-term interventions using high-velocity isokinetic or plyometric exercises has not been thoroughly investigated. OBJECTIVE: The aim of this study was to compare the effect of a lower body 3-week protocol using an isokinetic or a plyometric exercise program on strength and jump performance. METHODS: Thirty-six non-trained men were randomly allocated to the following three groups: (i) Isokinetic only (ISO, n= 12), performed 6 sets of 10 repetitions of concentric leg extension and flexion at 300∘⋅s-1 using an isokinetic dynamometer (Biodex-System-3); (ii) Plyometric only (PLY, n= 12) performed 6 sets of 10 repetitions of vertical jump; and (iii) Control, non-training group (n= 12). A 3-week training program involving two weekly workout sessions was implemented. Pre and post intervention measurements of knee extensor and flexor maximal peak torque, total work and average power at 300∘⋅s-1 and vertical jump performance were determined. RESULTS: Compared to baseline ISO significantly (p< 0.05) increased knee extension peak torque and average power. No other significant differences were observed at post-intervention or between groups. CONCLUSIONS: Compared to performing plyometric exercise alone, a 3-week intervention using only isokinetic training enhanced knee extensors strength. A more effective and specific neural adaptations driven by the isokinetic protocol over a short period of time could explain the observed responses.