Author(s): K B, S.1, KADAVIGERE, R.2, SUKUMAR, S.3, VAISHALI, K.1, Institution: MANIPAL COLLEGE OF HEALTH PROFESSIONS, Country: INDIA, Abstract-ID: 1638

INTRODUCTION:
Higher body mass index (BMI) and increased adiposity are associated with impaired cardiac autonomic regulation. Individuals with overweight typically demonstrate reduced parasympathetic activity and increased sympathetic dominance. Heart rate variability (HRV) is a non-invasive and reliable measure of autonomic modulation. Exercise training, particularly high-intensity interval training (HIIT), has been shown to induce favourable autonomic adaptations. However, limited evidence exists regarding the autonomic effects of short-term home-based HIIT in young adults with overweight. This study investigated the effects of a 6-week home-based HIIT programme on HRV in young adults with overweight.
METHODS:
A pre–post study was conducted recruiting 30 young adults with overweight (18-30 years, BMI 25-29.9 kg/m2) using a convenience sampling method. Resting HRV was recorded under standardised conditions at baseline. Participants then completed a 6-week home-based HIIT intervention, five sessions per week, 10 minutes per session at 14-17 on the RPE scale. Post-intervention resting HRV was measured using the same protocol. Time-domain (SDNN and RMSSD) and frequency-domain (HF, LF, LF/HF ratio) parameters were analysed. Paired t-tests were used to compare pre- and post-intervention HRV measures (p<0.05).
RESULTS:
No statistically significant differences were observed in any HRV parameters following the intervention (p>0.05; effect size 0.1). Descriptive statistics indicated a reduction in time-domain indices (SDNN and RMSSD) and a slight increase in certain frequency-domain measures compared to baseline; however, these changes did not reach statistical significance and should therefore be interpreted cautiously.
CONCLUSION:
Although trends in HRV parameters may suggest alterations in autonomic modulation, the absence of significant differences precludes definitive conclusions regarding changes in parasympathetic activity or sympathovagal balance. Larger, adequately powered studies are required to confirm these observations.