The effects of short-term high-intensity interval, moderate-intensity continuous and resistance training on cardiovascular health in older adults
Aging is associated with a decline in peripheral vascular endothelial function [i.e., flow-mediated dilation (FMD)] and cardiovagal baroreflex sensitivity (BRS), which are both critical to cardiovascular health. Accumulating evidence in younger adults suggest that high-intensity interval training (HIIT) provides superior benefits to cardiovascular health than moderate-intensity continuous training (MICT) and whole-body resistance training (RT). We tested whether 6-weeks of HIIT (n=6) improves upper- and lower-limb FMD and BRS more than MICT (n=9) and RT (n=8) in older adults (OA). FMD was assessed via high-resolution ultrasound. Cardiovagal BRS was assessed using Portapres® derived beat-by-beat systolic blood pressures and electrocardiogram-derived cardiac intervals via the ‘spontaneous baroreflex sequence’ method. Short-term HIIT and MICT elicited similar increases in BRS, brachial and popliteal FMD, whereas no changes were observed following RT. These results indicate that short-term aerobic training augments vascular health and blood pressure regulation more than RT in OA.