Effects of acute exercise programs on heart rate variability and vascular function in sedentary college students: A randomized controlled trial.

BACKGROUND

The specific effects of different exercises on cardiovascular health remain unclear. This study aimed to compare the effects of acute anaerobic threshold intensity continuous exercise (ATE), high-intensity interval training (HIIT), and stepwise incremental exercise (SIE) on heart rate variability (HRV) and vascular endothelial function in sedentary college students.

METHODS

Thirty-five sedentary students were randomized to the ATE group (20.6 ± 2.4 years), the HIIT group (21.7 ± 4.2 years), or the SIE group (21.2 ± 2.8 years). Brachial artery flow-mediated dilation was measured at 10 and 30 minutes after exercise. HRV was measured within 35 minutes postexercise.

RESULTS

It showed that the normalized low frequency postexercise was lower than baseline in the ATE group (P < .05). Flow-mediated dilation was decreased (P = .006) 30 minutes after exercise (6.4 ± 2.2%) compared to baseline (8.1 ± 1.4%) in the HIIT group and increased (+1.4%) in the ATE group with no statistical difference (P > .05). Significant correlations were detected between HRV frequency domain indices and brachial artery baseline diameter (P < .05).

CONCLUSION

Acute HIIT impairs vascular function 30 minutes after exercise, whereas acute ATE improves vascular function 10 minutes after exercise. Changes in vascular function may be related to changes in autonomic nervous system activity induced by acute exercise.