Does Exercise Training Improve Cardiac-Parasympathetic Nervous System Activity in Sedentary People? A Systematic Review with Meta-Analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of controlled intervention trials
PubMed 36360777 · doi:10.3390/ijerph192113899
What was done
Authors conducted a systematic review and meta-analysis of electronic searches in PubMed, Embase, and Web of Science to evaluate the effect of exercise training on cardiac parasympathetic nervous system activity in sedentary healthy adults. Outcomes of interest were resting heart rate variability (RMSSD and high frequency [HF] power) and post-exercise heart rate recovery (HRR). Random-effects models calculated between-group standardized mean differences (SMD), with heterogeneity assessed using chi-square and I² statistics, alongside subgroup and meta-regression analyses.
What was found
Exercise training produced statistically significant increases in cardiac parasympathetic markers compared to controls: - RMSSD: SMD = 0.57 (95% CI: 0.23 to 0.91; I² = 68%, p ≤ 0.001) - High frequency power: SMD = 0.21 (95% CI: 0.01 to 0.42; I² = 60%, p ≤ 0.001) - Greater training-induced increases in HF occurred in studies with shorter intervention duration or fewer exercise sessions (p ≤ 0.001). - Data were insufficient to analyze effects on post-exercise HRR.
Why it matters
This review quantifies the extent to which structured exercise training enhances cardiac parasympathetic modulation in previously inactive individuals, supporting exercise as an effective autonomic intervention.
Limits
The abstract does not state the number of included studies or total sample size. There was moderate and statistically significant between-study heterogeneity (I² = 60–68%). Data were insufficient to determine effects on post-exercise heart rate recovery, and results address parasympathetic modulation rather than baseline tone.
Cited by
- supports Aerobic exercise reduces resting heart rate and blood pressure and increases heart rate variability by enhancing parasympathetic innervation to the heart.