Effect of high-intensity endurance training on isokinetic muscle power

The purpose of this study was to determine the effects of high-intensity endurance training on isokinetic muscle power. Six male students majoring in physical-education participated in high intensity endurance training on a cycle ergometer at 90% of maximal oxygen uptake \(\dot V_{O_{2max} }\) for 7 weeks. The duration of the daily exercise session was set so that the energy expenditure equalled 42 kJ · kg⁻¹ of lean body mass. Peak knee extension power was measured at six different speeds (30°, 60°, 120°, 180°, 240°, and 300° · s⁻¹) with an isokinetic dynamometer. After training, \(\dot V_{O_{2max} }\) increased significantly from mean values of 51.2 ml · kg⁻¹ · min⁻¹, SD 6.5 to 56.3 ml · kg⁻¹ · min⁻¹, SD 5.3 (P < 0.05). Isokinetic peak power at the lower test speeds (30°, 60° and 120° · s⁻¹) increased significantly (P < 0.05). However, no significant differences in muscle peak power were found at the faster velocities of 180°, 240°, and 300° · s⁻¹. The percentage improvement was dependent on the initial muscle peak power of each subject and the training stimulus (intensity of cycle ergometer exercise).