High-intensity interval training: optimizing oxygen consumption and time to exhaustion taking advantage of the exponential reconstitution behaviour of D’

Abstract

PurposeAccumulating the time near maximum aerobic power left( {{dot{text{V}}text{O}}_{{{text{2max}}}} } right) is considered to be the most effective way to improve aerobic capacity. The aims of this study were: (1) to verify whether postponing the first recovery interval improves time to exhaustion during a high-intensity interval training (HIIT) test, and (2) to verify whether a HIIT protocol with decreasing interval duration (HIDIT) is more effective in accumulating time near {dot{text{V}}text{O}}_{{{text{2max}}}} compared with two classical protocols with short intervals (SIHIIT) and long intervals (LIHIIT).MethodsNine active males (35 ± 11 years, {dot{text{V}}text{O}}_{{{text{2max}}}} 52 ± 5 mL·min−1·kg−1) performed a graded exercise test on an athletic track. Critical velocity and D’ were estimated from three to five high-intensity trials to exhaustion. Then, the subjects performed three trials with a single recovery interval after 30 s (Rec30s), after 3 min (Rec3min) and after exhaustion (RecTlim) to verify whether postponing the first recovery interval enhances the time to exhaustion. Finally, the subjects performed the three HIIT protocols mentioned above.ResultsThe time to exhaustion was significantly greater in RecTlim (464 ± 67 s) than in Rec3min (388 ± 48 s) (p < 0.0078) and Rec30s (308 ± 44 s) (p > 0.0001). Additionally, it was significantly greater in Rec3min than in Rec30s (p = 0.0247). Furthermore, the time accumulated near {dot{text{V}}text{O}}_{{{text{2max}}}} was significantly longer in HIDIT (998 ± 129 s) than in SIHIIT (678 ± 116 s) (p = 0.003) and LIHIIT (673 ± 115 s) (p < 0.031).ConclusionsDuring the trials, postponing the first recovery interval was effective in improving the time to exhaustion. Moreover, HIDIT was effective in prolonging the time near {dot{text{V}}text{O}}_{{{text{2max}}}}.