Relative Aerobic and Anaerobic Energy Contributions during Short-Duration Exercise Remain Unchanged over A Wide Range of Exercise Intensities

The present study aimed to examine whether different exercise intensities, ranging from sub maximal to supramaximal, modulate the relative contributions of aerobic and anaerobic energy systems during short-duration exercise. Eight competitive male track and field athletes (22.3 ± 1.0 years) performed a 30-s pedaling test at seven different intensities corresponding to O 2 demands of 40, 50, 60, 70, 80, 90, and 100 ml/kg/min. The power outputs required at each O 2 demand were determined from the extrapolated linear relationships between power and the steady-state O 2 uptake obtained during submaximal-intensity exercise. The V 4 O 2 max test and 30-s Wingate anaerobic test were also performed. Relative aerobic and anaerobic energy contributions were estimated by the ratio of O 2 uptake and O 2 deficit, the latter being calcu lated as the difference between O 2 demand and O 2 uptake. The exercise intensity of the 30-s pedaling test ranged from 73.4 ± 7.4 to 180.9 ± 18.2% V 4 O 2 max. As exercise intensity increased, O 2 uptake (13.9 ± 2.1 to 26.8 ± 2.1 ml/kg/min) and O 2 deficit (26.9 ± 2.1 to 73.7 ± 2.2 ml/kg/min) during the 30-s pedaling test increased (P ˂ 0.05). However, the relative aerobic (34.1 ± 5.1 to 26.7 ± 2.0%) and anaerobic (65.9 ± 5.1 to 73.3 ± 2.0%) energy contributions during the 30-s pedaling test did not differ across all O 2 demands (P ˃ 0.05). These results suggest that the rel ative aerobic and anaerobic energy contributions during short-duration exercise remain nearly constant over a wide range of exercise intensity.