Comparative Analysis of Heart Rate Variability Parameters between Surya Namaskar and Stationary Bike Exercise Groups.

Background: Yoga practice has multiple health benefits. Surya Namaskar (SN) also known as sun salutation presents mental and physical health benefits equivalent to physical exercise. It consists of a sequence of 12 Hatha yoga postures with coordinated breathing.

Aims: This study evaluated the effect of SN against mild intensity stationary cycling exercise (SCE) on parameters of heart rate variability (HRV).

Methodology: This study was conducted in the department of physiology of a nationally important institute after obtaining ethics approval. A total of 40 healthy participants (males aged 46 ± 2.3 years) were enrolled in the study and divided into two groups, namely SN group and exercise group (SG and EG). The allocation on the group was based on subjects' choice and interest in performing SN or SCE. Baseline HRV, anthropometric measurement, and blood pressure were assessed. SG was subjected to 14 rounds of SN in about 20 min and EG to a 20-min mild-intensity stationary cycling session (30%-50% maximal heart rate). Assessments were conducted preexercise and postexercise recovery. HRV was assessed with the NeuralChek device.

Results: SN led to increased SDNN, pNN50, RMSSD, and total power, indicating improved autonomic balance, cardiovascular health, and parasympathetic dominance. Conversely, SCE decreased SDNN, pNN50, and RMSSD, suggesting immediate postexercise sympathetic dominance. Spectral analysis of HRV highlighted autonomic balance differences, with SN increasing low frequency (LF%) reflecting both sympathetic and parasympathetic dominance, whereas exercise reduced LF% due to sympathetic activation. Minimal changes were observed in high-frequency percentage. SN combines flexibility, strength, and balance, providing a balanced physical activity. This balance results in a mixed autonomic response, with sympathetic activity for the physical effort and parasympathetic activity for the relaxation components.

Conclusions: SN positively impacted HRV, promoting parasympathetic dominance and cardiovascular health, whereas exercise induced sympathetic activation with potential recovery benefits. Monitoring HRV offers insights into cardiovascular fitness and well-being. The study underscores the merits of incorporating yoga such as SN into daily activity routines.