Objective: It is not well known which exercise intensity is needed to obtain blood pressure reductions in response to endurance training. We therefore compared the effect of training at lower and higher intensity on blood pressure, and, in addition on other cardiovascular risk factors, in at least 55-year-old sedentary men and women.
Methods: We used a randomized crossover design comprising three 10-week periods. In the first and third periods, participants exercised at, respectively, lower and higher intensity (33 and 66% of heart rate reserve) in random order, with a sedentary period in between. Training programmes were identical except for intensity and were performed three times, 1 h per week. Thirty-nine (18 men) out of 48 randomized participants completed the study; age averaged 59 years.
Results: The change of aerobic power from baseline to the end of each period was more pronounced (P < 0.05) with higher intensity (+3.70 ml/kg min; P < 0.001) than with lower intensity training (+2.31 ml/kg min; P < 0.001). Systolic blood pressures at rest and during submaximal exercise were reduced with both intensities (P < 0.01), whereas diastolic office blood pressure was significantly reduced after higher intensity only (P < 0.01). There were no significant differences in blood pressure reduction between intensities. Ambulatory blood pressure remained unchanged after training. Only higher intensity training reduced weight (-1.09 kg; P < 0.001), body fat (-0.85%; P < 0.001), plasma triglycerides (-0.17 mmol/l; P < 0.05) and oxidized low-density lipoprotein (-5.92 U/l; P < 0.01).
Conclusion: Higher and lower intensity training reduces systolic office and exercise blood pressure to a similar extent, but does not alter ambulatory blood pressure; only higher intensity training favourably affects anthropometric characteristics and blood lipids.