CONSEQUENCES OF BRISK WALK, MODERATE INTENSITY CONTINUOUS AND HIGH INTENSITY INTERVAL TRAINING ON SHORT-TERM HEART RATE VARIABILITY IN HEALTHY YOUNG ADULTS

Abstract

Background: Short term heart rate variability is a time saving non-invasive measure of autonomic nervous system dysfunction. This study was conducted to assess and compare the effect of walking, medium intensity continuous and high-intensity interval training exercise modalities on short-term heart rate variability. Methods: This experimental study was conducted at the Department of Physiology, Islamic International Medical College, Rawalpindi, from August 2018 to August 2019. A total of 31 non-obese, healthy young individuals, free of comorbidities were included in the study. Participants were assigned through randomization to walk for 30 minutes intervention (n=10), medium intensity continuous training (MICT) intervention (n=11) and high-intensity interval training (HIIT) intervention (n=10). Intervention groups completed a total of 24 sessions in 7 weeks. Heart rate variability (HRV) analysis was performed by a 15-minute ECG recording before and after 24 sessions of intervention. ECGs were recorded by using the PowerLab^® model 4/25T and the data were analysed using the software LabChart^® Pro-8.0 with HRV 2.0 module installed. Results: After 24 sessions of 30-minute brisk walking exercise of 3,000 steps in an open area revealed a significant improvement in some HRV components when compared with pre-intervention levels of mean R-R interval (p=0.02), LFms2 (p=0.02) and LF/HF ratio (p=0.03). No significant differences were recorded after MICT and HIIT interventions among the groups. Conclusion: Compared to MICT and HIIT, a brisk walk in an open area was found to be effective mode of physical activity for improvement of HRV.

Pak J Physiol 2023;19(1):21–5