Abstract des Autors

The present study sought to evaluate the inconsistencies previously observed regarding the predominance of continuous or interval training for improving fitness. The experimental design initially equated and subsequently maintained the same relative exercise intensity by both groups throughout the program. Twelve subjects were equally divided into continuous (CT, exercise at 50 maximal work) or interval (IT, 30 s work, 30 s rest at 100 maximal work) training group that cycled 30 min/day, 3 days/week, for 8 weeks. Following training, aerobic power (VO2max), exercising work rates, and peak power output were all higher (9-16) after IT than after CT (5-7). Vastus lateralis muscle citrate synthase activity increased 25 after CT but not after IT. A consistent increase in adenylate kinase activity (25) was observed only after IT. During continuous cycling testing the CT group had reduced blood lactate (lab) levels and respiratory quotient at both the same absolute and relative (70 VO2max) work rates after training, while the IT group displayed similar changes only at the same absolute work rates. By contrast, both groups responded similarly during intermittent cycling testing with lower lab concentrations seen only at absolute work rates. These results show that, IT produces higher increases in VO2max and in maximal exercise capacity. Nevertheless, CT is more affective at increasing muscle oxidative capacity and delaying the accumulation of lab during continuous exercise.