Effects of different durations of aerobic exercise on the cardiovascular health in untrained women: a meta-analysis and meta-regression.

INTRODUCTION

Women's cardiovascular health is a hot topic. Exercise intervention is an effective method to improve the cardiovascular functions. The aim of this study was to systematically assess effects of aerobic exercise at different durations on the cardiovascular health of untrained women.

EVIDENCE ACQUISITION

Published articles from January 1989 to March 2016 were identified using electronic databases (PubMed, Cochrane Library, Embase and Web of Science) for randomized controlled trials. Weighted mean differences and 95% confidence intervals (CI) were calculated using fixed-effects and random-effects models. Meta-regression and subgroup analysis were performed to explore the possible heterogeneity.

EVIDENCE SYNTHESIS

Data from 26 published studies with a total of 518 untrained women were identified. The subgroup analysis and meta-regression were performed according to age (under 40, and from 41 to 60 years old) and exercise durations. Maximal oxygen consumption significantly increased at short-duration exercise (95% CI: -2.51 to -1.57; I2=0%) and mid-duration exercise (95% CI: -8.23 to -5.18; I2=0%). While HR (95% CI: 4.72 to 5.60; I2=0%) and SBP (95% CI: 5.55 to 7.52; I2=0%) significantly decreased at mid-duration exercise. Total cholesterol (N.=242, 95% CI: 0.07 to 0.16, I2=13%), HDL-C (N.=242, 95% CI: -0.11 to -0.06, I2=11%) and low-density lipoprotein cholesterol levels (N.=238, 95% CI: 0.07 to 0.16, I2=37%) significantly improved with short-duration, mid-duration and long-duration.

CONCLUSIONS

Improvement of cardiovascular functions decreases with age in untrained women. Short-duration exercise has significant effects on aerobic capacity. Mid-duration exercise significantly improves on aerobic capacity, heart rate and systolic blood pressure. All the different durations of aerobic exercise improve the cholesterol metabolism.