The purpose of this randomized controlled trial was to compare the effect of all-extremity high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on aortic pulse wave velocity (PWV) and carotid artery compliance in older adults.Methods
Forty-nine sedentary older adults (age = 64 ± 1 yr), free of overt major clinical disease, were randomized to HIIT (n = 17), MICT (n = 18), or nonexercise controls (CONT; n = 14). HIIT (4 × 4 min at 90% HRpeak interspersed with 3 × 3 min active recovery at 70% HRpeak) and isocaloric MICT (70% HRpeak) were performed on an all-extremity non–weight-bearing ergometer, 4 d·wk−1 for 8 wk under supervision. Aortic (carotid to femoral PWV [cfPWV]) and common carotid artery compliance were assessed at pre- and postintervention.Results
cfPWV improved by 0.5 m·s−1 in MICT (P = 0.04) but did not significantly change in HIIT and CONT (P > 0.05). Carotid artery compliance improved by 0.03 mm2·mm Hg−1 in MICT (P = 0.001), but it remained unchanged in HIIT and CONT (P > 0.05). Improvements in arterial stiffness in response to MICT were not confounded by changes in aortic or brachial blood pressure, HR, body weight, total and abdominal adiposity, blood lipids, or aerobic fitness.Conclusion
All-extremity MICT, but not HIIT, improved central arterial stiffness in previously sedentary older adults free of major clinical disease. Our findings have important implications for aerobic exercise prescription in older adults.