Effects of high-intensity interval training on cardiac function in hypertensive and normotensive men: Effects of antihypertensive treatment

Exercise training is recommended for individuals with hypertension because it has been shown to lower blood pressure and reverse left ventricular concentric remodelling and mass. However, it is unclear how hypertensive individuals respond in comparison to normotensive individuals and to what extent medical treatment affects the outcome of training. Our aim was to assess the effect of a 6 week high-intensity interval training (HIIT) intervention on cardiac adaptations in subjects with treated or untreated essential hypertension compared with normotensive control subjects. Cardiac function was evaluated by echocardiography in 11 medicated hypertensive men, who adhered to treatment during the intervention but refrained from medication for 4 days prior to and during measurements (MED-HYP), in 9 untreated hypertensive men (HYP) and in 10 age-matched normotensive men before and after HIIT. At baseline, HYP and MED-HYP had lower mitral valve E/A ratio (MED-HYP, 0.86 ± 0.2; HYP, 0.99 ± 0.1; P < 0.05) compared with normotensive men (1.37 ± 0.4). The HIIT stroke volume in normotensive men only improved maximum oxygen uptake (change, 178 ± 239 mL O₂/min). The E/e′ ratio (echocardiographic risk marker of cardiac events) increased (P < 0.05) with HIIT in MED-HYP, with no change in normotensive men and HYP. Men with treated and untreated essential hypertension display diminished cardiac adaptation and less improvement in cardiopulmonary fitness in response to HIIT compared with normotensive counterparts. Additionally, MED-HYP increased E/e′ with HIIT, potentially raising the risk of primary cardiac events. Therefore, further research is required to assess the interactive effects of exercise training and antihypertensive treatment.