Abstract
Although there are limited data to support significant increases in resting metabolic rate (RMR) following resistance training, recent investigations have shown excess post-exercise oxygen consumption (EPOC) to be significantly elevated above baseline for up to 72 hours in untrained and trained men. PURPOSE: To compare the effects of two acute bouts of resistance exercise of differing loads on EPOC. METHODS: Eight experienced resistance trained males (22 ± 3 yrs.) were recruited to participate in this investigation. Subjects participated in two randomized acute resistance training bouts separated by at least one week with a total volume of weight lifted of 10,000 kg and 20,000 kg. A high intensity lifting protocol was used with subjects lifting approximately 85% of their 1 repetition maximum for each of the following 4 lifts; bench press, barbell squat, barbell row and Romanian deadlift. Exercise energy expenditure and resting metabolic rate (RMR) were measured by indirect calorimetry during both exercise bouts and for 30 minutes approximately 8.5 and 1.5 hours prior to each acute bout of exercise (baseline measurements) and again approximately 12, 24, 36, and 48 hours following exercise. Creatine kinase and ratings of perceived muscle soreness were measured with all post exercise metabolic measurements and immediately prior to and post exercise. Repeated measures analysis of variance was used to analyze dependent measures. Significance was accepted at p<0.05. RESULTS: During the 20,000 kg lift subjects expended significantly (p<0.01) more energy (484 ± 29 kcal) than the 10,000 kg lift (247 ± 18 kcal). Twelve hour creatine kinase (1159 ± 729 U/L) was significantly elevated (p<0.05) from baseline (272 ± 280 U/L) and immediately post exercise (490 ± 402 U/L) following the 20,000 kg lift. No significant differences were found in RMR following exercise between the 10,000 kg and 20,000 kg lifts nor were any significant differences detected among baseline RMR and RMR over the 48 hours following either of the acute bouts of resistance exercise. DISCUSSION: Contrary to previously published investigations, high intensity resistance training with loads of up to 20,000 kg using experienced resistance trained males does not significantly increase EPOC above baseline RMR.
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