Background: Regular exercise is an effective intervention to decrease blood pressure (BP) in hypertension, but no data are available concerning the effects of heatedwater-based exercise (HEx). This study examines the effects of HEx on BP in resistant hypertensive patients

Methods: This is a parallel, randomized controlled trial. 125 nonconsecutive sedentary patients with resistant hypertension from a hypertension outpatient clinic in a university hospital were screened; 32 patients fulfilled the study requirements. The training was performed for 60-minute sessions in a heated pool (32 °C), three times a week for 12 weeks. The HEx protocol consisted of callisthenic exercises and walking inside the pool. The control group was asked to maintain habitual activities. The main outcome measure was change in mean 24-hour ambulatory BP

Results: 32 patients (HEx n = 16; control n = 16) were randomized; none were lost to follow-up. Office BPs decreased significantly after heated water exercise (36/12 mm Hg). HEx decreased 24-hour systolic (from 137 ± 23 to 120 ± 12 mm Hg, p = 0.001) and diastolic BPs (from 81 ± 13 to 72 ± 10 mm Hg, p = 0.009); daytime systolic (from 141 ± 24 to 120 ± 13 mm Hg, p b 0.0001) and diastolic BPs (from 84 ± 14 to 73 ± 11 mm Hg, p = 0.003); and nighttime systolic (from 129 ± 22 to 114 ± 12 mmHg, p=0.006) and diastolic BPs (from74 ± 11 to 66 ± 10mmHg, p b 0.0001). The control group after 12 weeks significantly increased in 24-hour systolic and diastolic BPs, and daytime and nighttime diastolic BPs

Conclusion: HEx reduced office BPs and 24-hour ABPM levels in resistant hypertensive patients. These effects suggest that HEx may be a potential new therapeutic approach in these patients