High-intensity interval training and cardiac autonomic modulation

Cardiac autonomic dysfunction is associated with various pathological conditions and is characterized by hyperactive sympathetic nervous system. Autonomic imbalance may lead to increased morbidity and mortality from various diseases and conditions, including cardiovascular disease. Exercise training is a cornerstone intervention for impaired autonomic function. However, the form of exercise which elicits maximum benefits in a time-efficient manner is a contentious issue. High-intensity interval training (HIIT) includes high-intensity bouts interspersed with low-intensity recovery. This is more acceptable form of exercise since the overload placed by high intensity bout leads to optimal adaptations and recovery provided by intermittent nature makes it more tolerable. This review article explains the effect of HIIT on cardiac autonomic function and the possible mechanisms underlying its positive effect.