Healthcare workers (HCWs) actively involved in patient care at tertiary care hospitals face significant stress and workload, which may adversely impact their sympatho-vagal balance (SVB). Research has extensively investigated SVB using various techniques, such as heart rate variability (HRV). With its multifaceted approach, yoga has been suggested to influence autonomic nervous system function and, consequently, SVB. Thus, this study aims to investigate the efficacy of a 4-week yoga module on SVB among HCWs. This randomised controlled trial will involve 108 HCWs aged 19-60 years. Participants will be randomised to either (1) a yoga intervention group or (2) a medium-paced walking control group. The primary outcome is a change in HRV after 4 weeks of intervention. Secondary outcomes comprise immediate change in state anxiety, selective attention and HRV compared pre- and post-intervention on days 1, 14 and 28. Intention-to-treat and per-protocol analysis will be performed to gain a comprehensive understanding of the effects of intervention. Multivariate linear model will adjust covariates in baseline HRV data in both groups. Independent t-test will compare pre- and postdata on all outcomes between groups. Paired t-test will be used to compare pre- and postdata on all outcomes within the group. The study protocol is registered on the Clinical Trials Registry - India (CTRI) (CTRI/2024/09/074132).