Behavior of Heart Rate Variability After 10 Repetitions Maximum Load Test for Lower Limbs

The purpose of this study was to analyze the acute heart rate variability behavior after 10 repetitions maximum load test for back squat, leg press, leg extension, and leg flexion in normotensive subjects. Eight recreationally trained women (age: 21.8 ± 2.2 yrs; height: 167.6 ± 6.3 cm; weight: 61.6 ± 10.1 kg) performed two 10 repetitions maximum testing days with 48-hours rest between each one. Heart rate variability was measured in baseline and postexercise (15-, 30-, 45-, and 60-minutes) for time and frequency domain. A significant difference was identified in RMSSD_ms (p = 0.010; effect size = -1.3), MRR_ms (p = 0.026; effect size = -1.3), MHR (p = 0.006; effect size = 1.4), and PNN50% (p = 0.006; effect size = -1.6) when compared 15 minutes postexercise with baseline. For all others comparison and index were no differences (p > 0.05). The present study demonstrates that load test, although works with maximum intensities, did not generate an exacerbated postexercise sympathetic activity. Thus, it seems to be safe for cardiovascular healthy individuals. As a practical application, these results can encourage exercise practitioners to do a maximum load test to resistance training loads prescription.