Effect of physical exercise on heart rate variability in overweight or obese individuals over 18 years of age : A systematic review and meta-analysis

Abstract

ABSTRACT: Introduction: Heart rate variability (HRV) is a tool that allows assessing the activity of the autonomic nervous system (ANS). Furthermore, there is evidence that positively relates physical activity (PA) to its balance and functionality. Objective: To determine the effect of physical exercise on HRV in overweight or obese adults (>18 years). Materials and methods: Cochrane, Medline, Embase, Lilacs and PEDro were systematically searched using the following search strategy: types of study: randomized controlled trials (RCTs) assessing the effect of PA-based interventions on HRV parameters in overweight or obese adults; publication period: January 2015-June 2021; language: English; search terms: MeSH terms combined with Boolean operators “AND” and “OR”. The literature review protocol was registered in PROSPERO (code: CRD42021224027). The risk of bias was assessed using the Cochrane risk of bias assessment tool. A random-effects meta-analysis was performed to estimate the pooled effect for each outcome variable (HRV parameter) when data could be pooled. Subgroup analyses were also performed to make comparisons between the different interventions. A significance level of p<0.05 was considered. Results: The initial searches yielded 2650 studies, but only 11 RCTs met the inclusion criteria. There were no statistically significant differences between the intervention and control groups in terms of changes in HRV parameters after completing the intervention SDNN: (WMD=1. 30, 95%CI: -5.93-8.53, p=0.72); RMSSD: (WMD=0.79, 95%CI: -0.29-1.87, p=0.15); HF: (WMD=6.67, 95%CI:1.71-11.63, p=0.008), and LF: (WMD= -0.32, 95%CI: -0.73-0.10; p=0.13). Conclusion: Although results were not statistically conclusive, there were clinically important changes in HRV parameters in the intervention groups.