High-intensity intermittent swimming improves cardiovascular health status for women with mild hypertension

To test the hypothesis that high-intensity swim training improves cardiovascular health status in sedentary premenopausal women with mild hypertension, sixty-two women were randomized into high-intensity (n=21; HIT), moderate-intensity (n=21; MOD), and control groups (n=20; CON). HIT performed 6–10 × 30 s all-out swimming interspersed by 2 min recovery and MOD swam continuously for 1 h at moderate intensity for a 15-week period completing in total 44±1 and 43±1 sessions, respectively. In CON, all measured variables were similar before and after the intervention period. Systolic BP decreased (P<0.05) by 6±1 and 4±1 mmHg in HIT and MOD; respectively. Resting heart rate declined (P<0.05) by 5±1 bpm both in HIT and MOD, fat mass decreased (P<0.05) by 1.1±0.2 and 2.2±0.3 kg, respectively, while the blood lipid profile was unaltered. In HIT and MOD, performance improved (P<0.05) for a maximal 10 min swim (13±3% and 22±3%), interval swimming (23±3% and 8±3%), and Yo-Yo IE1 running performance (58±5% and 45±4%). In conclusion, high-intensity intermittent swimming is an effective training strategy to improve cardiovascular health and physical performance in sedentary women with mild hypertension. Adaptations are similar with high- and moderate-intensity training, despite markedly less total time spent and distance covered in the high-intensity group