The Influence of Physical Exercise, Stress and Body Composition on Autonomic Nervous System: A Narrative Review

The heart rate variability (HRV) changes under different situations such as physical exercise, stress and in obese/ overweight subjects. It is considered a noninvasive marker of autonomic nervous system function. The aim of this narrative review was to discuss the relationship between HRV and physical exercise. Moreover, we will make an overview about HRV and stress, and HRV and body composition. There are a large number of studies dealing with HRV, however, few of them explain relationship between HRV and physical exercise, stress and body composition. HRV has proved to be a valuable tool to investigate the sympathetic and parasympathetic function of the ANS. Nonlinear parameters can be used to analyze the health of the subjects and is also used to investigate the stress and the physical exercise level. Despite the underlying mechanisms remain to be elucidated, these finding can be used as a starting point to determine a non-invasive index of cardiac wellness for clinical and nutritional applica- tion. Thus, physiological feedback via monitoring HRV would prove useful for addressing the individual’s present capability, be it during selection processes or returning to duty following injury or illness but should not be used to diagnose any pathological conditions.