Resistance and aerobic exercise have similar effects on 24-h nutrient oxidation.
Level 2 - randomized trial
Controlled crossover clinical trial measuring human metabolic responses across three conditions
PubMed 12439085 · doi:10.1097/00005768-200211000-00016
What was done
Ten nonobese male subjects completed three conditions inside a whole-room indirect calorimeter to compare 24-h energy expenditure (EE) and macronutrient oxidation. The three conditions were stationary cycling (BK; 49 ± 7 min at 70% VO2max), circuit weightlifting (WTS; 70 min, 4 sets of 10 exercises at 70% 1RM), and a non-exercise control day (Con).
What was found
Active exercise energy expenditure was higher during BK (546 ± 16 kcal) than WTS (448 ± 21 kcal, P < 0.001). Total 24-h EE was significantly elevated on both BK (2,787 ± 76 kcal/day) and WTS days (2,730 ± 106 kcal/day) compared to Con (2,260 ± 96 kcal/day, P < 0.001), with no significant difference between exercise types (P > 0.05). 24-h carbohydrate oxidation was significantly higher on exercise days (BK = 370 ± 18 g/day, WTS = 349 ± 23 g/day) compared with Con (249 ± 29 g/day, P = 0.04). 24-h respiratory exchange ratio, 24-h fat oxidation, and 24-h protein oxidation did not differ across BK, WTS, and Con days. Post-exercise EE and macronutrient oxidation were also not significantly different across conditions.
Why it matters
This study shows that acute resistance exercise and aerobic exercise have comparable effects on 24-hour daily energy expenditure and substrate utilization. It also demonstrates that neither exercise modality acutely enhances 24-hour net fat oxidation above baseline control levels.
Limits
The study was limited to a very small cohort (n = 10) of nonobese men, precluding generalization to women, older adults, or individuals with obesity. It only evaluated acute 24-hour responses in a metabolic chamber, which does not reflect long-term training adaptations or body composition changes.
Cited by
- supports Acute fat oxidation during or immediately after exercise does not meaningfully offset 24-hour total energy metabolism to produce greater long-term body fat loss.