Heart rate variability and blood pressure during and after three CrossFit? sessions

CrossFit (R) is a training program characterized by high intensity stimulus with constantly varied and multifunctional movements that induces a significant range of physiological, hemodynamic and biochemical responses. Heart rate variability (HRV) can be used to measure how individuals react to physiological stress and fatigue. Thus, the aim of this study was to verify HRV and blood pressure acute responses during and after three sessions of Crossfit (R). Nine subjects with more than one year of experience performed three different sessions of CrossFit (R) to verify the response of systolic blood pressure (SBP), diastolic blood pressure (DBP) and HRV. Significant reductions in HRV were observed through parasympathetic indexes (High Frequency(HF), p < 0.001) and an increase in the activity of sympathetic indexes (Low Frequency (LF), p < 0.01; LF/HF, p < 0.001) after all Crossfit (R) workouts. SBP decreased (p < 0.05) and there were no significant differences between workouts of the day in both HRV and SBP. Different CrossFit (R) sessions induced similar activity of the autonomic nervous system with reduced HRV and post-exercise hypoten-sion.