Effects of physical activity on heart rate variability in children and adolescents: a systematic review and meta-analysis

Effect of resistance training on heart rate variability of anxious female college students

Introduction

Female college students are a group with high incidence of anxiety, and anxiety will lead to the disorder of autonomic nervous system (ANS), which will adversely affect their study and life. Resistance training plays a positive role in improving anxiety, but there is little evidence on whether resistance training can improve ANS of anxious female college students. Heart rate variability (HRV) has gained widespread acceptance in assessing ANS modulation. Therefore, the objective of this study aimed to investigate the effects of resistance training on heart rate variability (HRV) in anxious female college student.

Methods

A randomized controlled study of resistance training intervention was conducted in 27 anxious female college students that assigned randomly into an intervention group (n = 14) and a control group (n = 13). The intervention group was intervened by cluster training for 8 weeks. Self-rating anxiety scale (SAS) was used. ANS is evaluated by short-term HRV. Muscle strength was assessed by 1 RM indirect method. Independent-sample t-test was used to test post-test-pre-test scores between the intervention and control groups.

Results

After the intervention, SAS score of the intervention group was significantly decreased (P < 0.05), SDNN of the intervention group was significantly increased (P < 0.05) and LF/HF was significantly decreased (P < 0.05).

Conclusion

The resistance training intervention adopted in this study significantly increased the HRV of anxious female college students and improved their autonomic nervous disorder.

Heart Rate Variability and Laboratory-Based Loss-of-Control Eating in Children and Adolescents

Among youth, greater heart rate (HR) and lesser HR variability (HRV) are precursors to loss-of-control (LOC) eating episodes in the natural environment. However, there are limited data examining whether pre-meal HR and HRV are associated with greater LOC-eating in the laboratory setting. We therefore examined temporal relationships between pre-meal HR, frequency- and time-based metrics of pre-meal HRV, perceived LOC-eating, and energy intake during a meal designed to simulate a LOC-eating episode. Among 209 participants (54.5% female, 12.58 ± 2.72 years, 0.52 ± 1.02 BMIz), 19 reported LOC-eating in the prior month. Perceived LOC-eating during the laboratory meal was not significantly linked to pre-meal HR (p = 0.37), but was positively related to pre-meal HRV (ps = 0.02–0.04). This finding was driven by youth with recent LOC-eating, as these associations were not significant when analyses were run only among participants without recent reported LOC-eating (p = 0.15–0.99). Pre-meal HR and HRV were not significantly related to total energy intake (ps = 0.27–0.81). Additional research is required to determine whether early-stage pediatric LOC-eating is preceded by a healthy pre-meal stress response. Longitudinal studies could help clarify whether this pattern becomes less functional over time among youth who develop recurrent LOC-eating episodes.