Heart Rate Variability Changes Following Treadmill Running in Sedentary Obese Individuals: A Pre–Post Interventional Study

Background: The normal state of the autonomic nervous system is reflected in heart rate variability (HRV), which is often impaired in obesity. Aerobic exercise can improve HRV, but evidence for treadmill running in sedentary obese adults is limited. Objectives: To assess the impact of treadmill running on HRV in healthy sedentary obese adults through pre- and postintervention analysis. Materials and Methods: Forty-one sedentary obese adults (body mass index ≥30, 17–25 years) at Srinivas University, Mangalore, completed a 6-week treadmill program (5 days/week, 45-min moderate-intensity sessions). HRV (SDNN, SDNN index, HF, LF, and VLF), heart rate, and blood pressure were assessed at baseline, 5, 15, and 45 days postintervention. Results: Significant improvements were observed in HRV parameters (SDNN, SDNN Index, HF, LF, and VLF; P < 0.001). Average and minimum heart rates decreased when the highest heart rate was raised ( P < 0.001). Systolic blood pressure dropped at 45 days, and diastolic blood pressure remained unchanged. Conclusion: 45 days of treadmill running was associated with improvements in HRV indices in sedentary obese young adults, suggesting favorable autonomic changes. Blood pressure remained largely unchanged, while heart rate measures showed modest reductions. Due to the pre–post design without a control group, causal conclusions cannot be drawn. Larger randomized studies are needed to confirm these findings.