Though exercise regimens vary in content and duration, few studies have compared the caloric expenditure of multiple exercise modalities with the same duration. The purpose of the present study was to compare the energy expenditure of single sessions of resistance, aerobic, and combined exercise with the same duration. Nine recreationally active men (25 +/- 7 years; 181.6 +/- 7.6 cm; 86.6 +/- 7.5 kg) performed the following four exercises for 30 minutes: a resistance training session using 75% of their 1 repetition maximum (1RM), an endurance cycling session at 70% maximum heart rate (maxHR), an endurance treadmill session at 70% maxHR, and a high-intensity interval training (HIIT) session on a hydraulic resistance system (HRS) that included repeating intervals of 20 seconds at maximum effort followed by 40 seconds of rest. Total caloric expenditure, substrate utilization, heart rate, and rating of perceived exertion (RPE) were recorded. Caloric expenditure was significantly (p < 0.05) greater when exercising with the HRS (12.62 kcal/min +/- 2.36), compared to weights (8.83 kcal/min +/- 1.55), treadmill (9.48 kcal/min +/- 1.30) and cycling (9.23 kcal/min +/- 1.25). Average heart rate was significantly (p < 0.05) greater with the HRS (156 beats/min +/- 9), compared to weights (138 beats/min +/- 16), treadmill (137 beats/min +/- 5) and cycling (138 beats/min +/- 6). Similarly, average RPE was significantly (p < 0.05) higher with the HRS (16 +/- 2), compared to weights (13 +/- 2), treadmill (10 +/- 2) and cycle (11 +/- 1). These data suggest that individuals can burn more calories performing a HIIT session with a HRS than spending the same amount of time performing a steady-state exercise session. This form of exercise intervention may be beneficial to individuals who want to gain the benefits of both resistance and cardiovascular training but have limited time to dedicate to exercise.
Copyright (C) 2014 by the National Strength & Conditioning Association.