The Maintenance of Anaerobic Power in Intermittent Short-Duration High Intensity Exercise

Abstract

1427 Anaerobic power is defined as the ability to produce high mechanical power output in a short time and provides a quantitative measure of anaerobic fitness. Many sports demand intermittent anaerobic energy production. Depletion of creatine phosphate and accumulation of lactate that results in a decrease in muscle pH are limiting factors in muscle work. The maintenance of anaerobic power output for high intensity intermittent exercises is important in competitive sports events. PURPOSE: The purpose of this study was to determine the optimal exercise-resting time for maintaining a high mechanical power output in intermittent short-duration cycle exercise. METHODS: Eleven male healthy students of physical education (18.4 ± 0.5 years, 174.7 ± 4.4 cm, 71.2 ± 3.3 kg, Vo2max 46.5 ± 3.0 ml/kg/min) participated in this study. Subjects performed ten bouts of maximal cycle exercise (0.931 kp per body weight) with rest period, and blood lactate concentration, oxygen uptake, peak power, and mean power output were measured. The measurements were repeated four exercise conditions (3-, 5-, 7-, and 10-s exercise with 57-, 55-, 53-, and 50-s rest period, respectively) in a laboratory. RESULTS: In 3- and 5-s exercise, peak power and mean power did not show any significant decrease during ten bouts exercise. In 7- and 10-s exercise, both peak power and mean power were decreased whenever number of the exercise bouts increased. Fatigue index decreased (3-s, 102 ± 4; 5-s, 94 ± 4; 7-s, 83 ± 5; 10-s, 73 ± 8 %), whilst blood lactate concentration increased with bout length increment (3-s, 4.3 ± 0.1; 5-s, 7.8 ± 1.1; 7-s, 9.9 ± 0.9; 10-s, 11.2 ± 1.3 mmol/l). The significant positive correlation between cumulative work and blood lactate concentration (r = 0.880, p < 0.001), and negative correlations of peak power with blood lactate (r = 0.890, p < 0.001), and with oxygen uptake (r = 0.807, p < 0.001) were found under four exercise conditions. CONCLUSIONS: Increase in the performance of intermittent exercise seems to require the adaptations both of an aerobic energy production and concomitantly of an anaerobic one. In order to maintain the mechanical power output during intermittent short-duration cycle exercise, the present results suggest that the optimal exercise-resting time is between 3–57 and 5–55 seconds protocol. This finding will provide a valuable information for athletes planning a training program to improve endurance of anaerobic power for competitive sports events.