Acute Behavior of Oxygen Consumption, Lactate Concentrations, and Energy Expenditure During Resistance Training: Comparisons Among Three Intensities

Purpose

This study aimed to compare the oxygen consumption, lactate concentrations, and energy expenditure using three different intensities during the resistance training sessions. 

Methods

A total of 15 men (22.9 ± 2.61 years) experienced in resistance training underwent 3 sessions composed of 8 exercises (chest press, pec deck, squat, lat pull-down, biceps curl, triceps extension, hamstring curl, and crunch machine), which were applied in the same order. The weight lifted differed among the sessions [high session: 6 sets of 5 repetitions at 90% of 1-repetition maximum (1-RM); intermediary session: 3 sets of 10 repetitions at 75% of 1-RM; and low session: 2 sets of 15 repetitions at 60% of 1-RM]. The oxygen consumption (VO₂)—during and after (excess post-exercise oxygen consumption (EPOC)) the session, blood lactate concentration, and energy expenditure (i.e., the sum of aerobic and anaerobic contributions, respectively) were assessed. 

Results

The VO2 significantly decreased in the function of the weight lifting (F_(2.28) = 17.02; p < 0.01; η_G² = 0.32). However, the aerobic contributions significantly increase in the function of the weight lifting (F_(2.28) = 79.18; p < 0.01; η_G² = 0.75). The anaerobic contributions were not different among the sessions (p > 0.05; η_G² < 0.01). Thus, the total energy expenditure during the session (kcal) significantly increased in the function of the weight lifting (F_(2.28) = 86.68; p < 0.01; η_G²) = 0.75). The energy expenditure expressed in time unit (kcal·min⁻¹) was higher in low session than in high session (F_(2.28) = 6.20; p < 0.01; η_G² = 0.15). 

Conclusion

The weight lifted during resistance training-induced different physiological responses, which induced higher energy expenditure per unit of time during the low session.