Effect of muscle strength at different intensities on resting energy expenditure

Introduction: the regular practice of physical exercise is an important modulator of resting energy expenditure (REE), which depending on the intensity, duration, and type of exercise can increase the REE in an acute manner as well as long term. The effects of dynamic muscular strength exercises on the REE have been treated very little in literature. Objective: compare the effect of muscle strength exercise (MSE) at different intensities on the REE in young males. Methods: Intra-group design. Fourteen subjects aged 22,5±1,5 <active (IPAQ= MET≥3000 week), realized two sessions of strength exercises at 2 intensities (40% and 80%RM), in 3 types of exercises (90° Squats; Bicep Curls, and Upright Row). Each session evaluated the same number of sets (3), repetitions (6), and rest time between sets (2min.). The REE was measured beforehand, immediately after, and 24 hours after by indirect calorimetry. Results: The REEpost (kcal/day) increased after the MSE at 40%RM, (p<0,05; CI=1950,67-2215,62) and at 80%RM, (p<0,001; CI=1947,10-2154,62), for a high and moderate effect size respectively. Differences in the % of change for both intensities (p<0,05) and a high effect size for 40%RM and moderate for 80%RM were found. No differences were found in the comparison (kcal/day) between REEpre y REEpost 24h (p>0,05) after the exercise at 40%RM. The REEpost 24h was maintained according to the REEpre when the intensity was 80%RM. Conclusion: The REEpost exercise is independent of the intensity of the exercise and only is maintained after 24 hours when the MSE is at a high intensity.