Effect of high intensity Interval training on the autonomic nervous system

High intensity interval training (HIIT) has become a strategic and novel training method to improve cardiovascular indicators, however, studies of the chronic effect on heart rate variability are limited. Objective: To determine the sub-chronic effect of a HIIT on the autonomic nervous system in sedentary adults. Method: 20 apparently healthy sedentary adults (33.3 & PLUSMN;5.2 years) participated, who were estimated to have their final intermittent speed. The interval training program consisted in 16 sessions with 48-hour breaks between them. Autonomic nervous system response was assessed by heart rate variability and stress score. Results: No significant differences (p < .05) were found between the HIIT program sessions on the stress index and the heart rate variability. Conclusion: The high intensity interval training did not show chronic alterations in the autonomic nervous system, so this type of training does not generate stress or overload in the sedentary population.