High-intensity interval training for reducing blood pressure: a randomized trial vs. moderate-intensity continuous training in males with overweight or obesity

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.