Running to Lower Resting Blood Pressure: A Systematic Review and Meta-analysis

Background According to previous epidemiological studies, there are pros and cons for the relationship between running regularly and changes in resting blood pressure (RBP), and the changes may depend on the form of exercise. Objective The aims of the current systematic review were to summarize the effects of running regularly on RBP and to investigate the most efficacious form of running in reducing RBP for this purpose. Methods The inclusion criteria were: randomized controlled trials, involving healthy adults or adults with hypertension, the exercise group only performed regular running and the control group did not exercise, and the study reported the mean resting systolic blood pressure (RSBP) and/or diastolic blood pressure (RDBP). The mean difference (MD) in RBP in each trial was defined as follows: (mean value at post-intervention in the exercise group - mean value at baseline in the exercise group) - (mean value at post-intervention in the control group - mean value at baseline in the control group) and was calculated. The weighted MD (WMD) was defined as the synthesis of all MD. A linear meta-regression analysis, exercise intensity [the percentage of maximum heart rate] (%) and total exercise time throughout the intervention (hours) were selected as explanatory variables and the MD in RBP served as the objective variable. Results Twenty-two trials (736 subjects) were analyzed. When trials were limited to those involving healthy subjects, the WMD in RBP decreased significantly [RSBP: - 4.2 mmHg (95% confidence intervals (95% CI) - 5.9 to - 2.4); RDBP: - 2.7 mmHg (95% CI - 4.2 to - 1.1)] and did not contain significant heterogeneity (RSBP: P = 0.67, I-2 = 0.0%; DBP: P = 0.38, I-2 = 7.2%). When trials were limited to those involving subjects with hypertension, the WMD in RBP decreased significantly [RSBP: - 5.6 mmHg (95% CI - 9.1 to - 2.1); RDBP: - 5.2 mmHg (95% CI - 9.0 to - 1.4)] but contained significant heterogeneity (RSBP: P = 0.01, I-2 = 62.2%; DBP: P < 0.01, I-2 = 87.7) and a meta-regression analysis showed that the percentage of maximum heart rate was significantly associated with the WMD in RSBP [slope: 0.56 (95% CI 0.21 to 0.92), intercept: - 48.76 (95% CI - 76.30 to - 21.22), R-2 = 0.88] and RDBP [slope: 0.45 (95% CI 0.01 to 0.87), intercept: - 38.06 (95% CI - 72.30 to - 4.08), R-2 = 0.41]. When trials were limited to those involving subjects with hypertension and a mean age >= 40 years, a meta-regression analysis showed that total exercise time throughout the intervention was significantly associated with the WMD in RDBP [slope: 0.82 (95% CI 0.54 to 1.09), intercept: - 22.90 (95% CI - 29.04 to - 16.77), R-2 = 0.99]. Conclusions Running regularly decreases RBP, but the changes in subjects with hypertension may differ depending on exercise intensity or total exercise time. Therefore, running regularly at moderate intensity and at a restrained volume is recommended to lower RBP in subjects with hypertension.