High-intensity interval training for reducing blood pressure: a randomized trial vs. moderate-intensity continuous...

The optimal exercise-training characteristics for reducing blood pressure (BP) are unclear. We investigated the effects of 6-weeks of high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT) on BP and aortic stiffness in males with overweight or obesity. Twenty-eight participants (18-45 years; BMI: 25-35 kg/m²) performed stationary cycling three times per week for 6 weeks. Participants were randomly allocated (unblinded) to work-matched HIIT (N = 16; 10 × 1-min intervals at 90-100% peak workload) or MICT (N = 12; 30 min at 65-75% peak heart rate). Central (aortic) and peripheral (brachial) BP and aortic stiffness was assessed before and after training. There were no significant group × time interactions for any BP measure (all p > 0.21). HIIT induced moderate reductions in central (systolic/diastolic ∆: -4.6/-3.5 mmHg, effect size d = -0.51/-0.40) and peripheral BP (-5.2/-4 mmHg, d = -0.45/-0.47). MICT induced moderate reductions in diastolic BP only (peripheral: -3.4 mmHg, d = -0.57; central: -3 mmHg, d = -0.50). The magnitude of improvement in BP was strongly negatively correlated with baseline BP (r = -0.66 to -0.78), with stronger correlations observed for HIIT (r = -0.73 to -0.88) compared with MICT (r = -0.43 to -0.61). HIIT was effective for reducing BP (~3-5 mmHg) in the overweight to obese cohort. Exercise training induced positive changes in central (aortic) BP. The BP-lowering effects of exercise training are more prominent in those with higher baseline BP, with stronger correlation in HIIT than MICT.