OBJECTIVE: To assess the effect of two recovery intervals (RIs) between sets of isokinetic knee extension exercises on peak torque (PT) and total work (TW), among untrained young men. METHODS: Eighteen men (24.22±2.58 years; 80.42±11.41 kg) performed three sets of ten isokinetic extensions of the right knee, at 60° and 180°/s. The RIs between the sets were one and two minutes long, spread over two test days separated by a minimum of 48 hours. The work-to-recovery ratio was 1:3 and 1:6 for 60°/s, and 1:6 and 1:12 for 180°/s. The subjects had not participated in any resistance training programs within the last six months. The statistical analysis consisted of 2 x 3 repeated-measures ANOVA [RI (one or two minutes) x set (1st, 2nd or 3rd)]. The significance level was a<0.05. RESULTS: Neither one minute nor two minutes RIs maintained the PT and TW throughout the three sets (p<0.05). However, at 60°/s, two minutes RIs enabled better PT and TW in the second and third sets than one minute RIs (p<0.05). At 180°/s, two minutes RIs were only better (p<0.05) than one minute RIs for TW in the third set. CONCLUSION: This study indicated that, during an isokinetic training protocol, young men require more than two minutes of RI for full PT recovery at 60°/s and full TW recovery at 60°/s and 180°/s. However, better PT recovery can be attained with a 1:12 work-to-recovery ratio at 180°/s.
torque; muscle fatigue; quadriceps muscle; knee extension
