LAUSR

PurposeThis study was designed to analyze the differences in metabolic indicators and energy expenditure (EE) between two models of health club fitness classes: Aerobic Fitness Class (AFC) and Strength Fitness Class (SFC).MethodsFifteen adult women (mean ± standard deviation: age, 29.0 ± 3.3 years; height, 161.8 ± 4.8 cm; body mass index, 21.5 ± 1.6 kg/m2) participated in the present study. Maximum oxygen uptake (VO2max) and maximum heart rate (HRmax) were measured directly during a maximal treadmill test. During AFC and SFC sessions, heart rate (HR), oxygen uptake (VO2), respiratory exchange ratio (RER), metabolic equivalents (MET), percentage of fat oxidation (%FAT), percentage of carbohydrate oxidation (%CHO) and EE were assessed by indirect calorimetry using a portable gas analyzer (K4b2). Student’s paired samples t test was used to analyze differences between AFC and SFC. Significance level was set at 5%. Effect sizes (Cohen’s d) were observed.ResultsThere were greater values during AFC in comparison with SFC on the following variables: VO2 (1959.3 ± 273.2 vs. 1122.7 ± 187.7 ml kg−1 min−1; p < 0.001; ES = 3.69); HR (161 ± 14 vs. 133 ± 17 bpm; p < 0.001; ES = 1.86); MET (10.0 ± 1.2 vs. 5.8 ± 0.9 MET; p < 0.001; ES = 4.1); total EE (259.6 ± 24.9 vs. 151.7 ± 22.3 kcal; p < 0.001; ES = 4.73);  %VO2max (76.9 ± 8.6 vs. 44.3 ± 8.1%; p < 0.001; ES = 4.04);  %HRmax (84.2 ± 5.8 vs. 69.7 ± 7.9%; p < 0.001; ES = 2.17) and CHO oxidation rate (139.9 ± 16 vs. 82.4 ± 13.8 kcal h−1; p < 0.001; ES = 3.98). Further, CHO was the main substrate for both classes.ConclusionThese results suggest that AFC induces greater EE than SFC. Moreover, engaging AFC or SFC 3–5 times a week seems enough to achieve international physical activity recommendations per week to promote several health benefits. Finally, carbohydrate is the main energy supply for both types of fitness classes.