Effect of endurance training on blood pressure regulation, biomarkers and the heart in subjects at a higher age.

We reported previously that two otherwise identical training programs at lower (LI) and higher intensity (HI) similarly reduced resting systolic blood pressure (BP) by approximately 4-6 mmHg. Here, we determined the effects of both programs on BP-regulating mechanisms, on biomarkers of systemic inflammation and prothrombotic state and on the heart. In this cross-over study (3 × 10 weeks), healthy participants exercised three times 1 h/week at, respectively, 33% and 66% of the heart rate (HR) reserve, in a random order, with a sedentary period in between. Measurements, performed at baseline and at the end of each period, involved blood sampling, HR variability, systolic BP variability (SBPV) and cardiac magnetic resonance imaging. Thirty-nine participants (18 men; mean age 59 years) completed the study. Responses were not different between both programs (P>0.05). Pooled data from LI and HI showed a reduction in HR (-4.3 ± 8.1%) and an increase in stroke volume (+11 ± 23.1%). No significant effect was seen on SBPV, plasma renin activity, basal nitric oxide and left ventricular mass. Our results suggest that the BP reduction observed appears to be due to a decrease in systemic vascular resistance; training intensity does not significantly affect the results on mechanisms, biomarkers and the heart.