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 G 2 = 0.32). However, the aerobic contributions significantly increase in the function of the weight lifting (F (2.28) = 79.18; p < 0.01; η G 2 = 0.75). The anaerobic contributions were not different among the sessions (p > 0.05; η G 2 < 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 G 2 = 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 G 2 = 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.

Kallikrein kinin system activation in post-exercise hypotension in water running of hypertensive volunteers.

Previous studies demonstrated a reduction in blood pressure level immediately after different types of exercises, like running, cycling and resistance training, a phenomenon called post-exercise hypotension (PEH). Since PEH can persist for hours it could be suggested as a non-pharmacological therapy for hypertensive individuals. Unfortunately, usually running is not recommended due to the high impact caused by its practice. Therefore running in water treadmill should be a better option, since the environment is completely different and causes lower impact. However it is not known whether PEH occurs in this situation. The objective of this work was to evaluate the existence of PEH after water running and to compare PEH promoted by running in two different environments. In addition, changes in plasmatic concentrations of the kallikrein kinin system (KKS) components were also evaluated. Sixteen hypertensive subjects were submitted to two exercise sessions, conventional running and water running, in two different occasions. The pattern of heart rate, blood pressure and plasmatic concentrations of KKS components immediately after and one hour after exercise were investigated. Results showed a maximal reduction in systolic and diastolic blood pressure 30 min after both exercise models (P<0.001), indicating that moderate water running promotes PEH with similar magnitude as compared to conventional running. Plasma kallikrein activity and bradykinin concentration increased immediately after exercise (P<0.05), but these parameters were not different in both exercise models. In conclusion, our findings show that water running, similarly to conventional running, can also provoke PEH and alterations in the KKS components.