Recovery Metabolism Following High Intensity Intermittent Exercise

Abstract

Tremblay et al. (1994) have shown that regular short intermittent high intensity exercise results in significantly greater fat loss compared to continuous steady state exercise. A possible mechanism underlying this fat loss may be excess post-exercise oxygen consumption (EPOC). PURPOSE: the purpose of this study was to determine the effects of intermittent high intensity exercise upon EPOC among untrained college-aged women. METHODS: seven females, aged between 19–23 years were required to undergo two cycle ergometry testing sessions; a VO2peak test, and 20 min of short high intermittent intensity exercise (8 s sprint, 12s recovery). Resting metabolic rate (RMR) was assessed before and after the high intensity exercise bout. A ramped bicycle test was administered to determine VO2peak and lactate threshold. On a separate day, power outputs eliciting energy expenditures at an RER of .93 were continued for 20 min in the 8 s sprint condition. Blood samples were collected from an antecubital vein at rest, every 5 min during exercise, and throughout a 60-min recovery from the high intensity exercise. Ventilatory and heart rate measurements were recorded throughout exercise and during recovery. RESULTS: heart rate, RER, glycerol, lactate, and EPOC were significantly elevated (p<0.001) 10 min after exercise. Heart rate, glycerol, and lactate, had returned to baseline levels after 30 min of recovery but EPOC was still significantly elevated and RER was significantly lower than baseline at 60 min (p<0.05). There was a strong positive correlation between resting insulin resistance and RER at 60 min (r=0.94, p = 0.005). CONCLUSIONS: 20 min of short intermittent high intensity exercise incurred a significant EPOC response, however, women with insulin resistance displayed impaired fat metabolism post exercise.