Effects of exercise intensity and cardiorespiratory fitness on the acute response of arterial stiffness to exercise in older adults.
PURPOSE
Increased arterial stiffness is observed with ageing and in individuals with low cardiorespiratory fitness ([Formula: see text]O2peak), and associated with cardiovascular risk. Following an exercise bout, transient arterial stiffness reductions offer short-term benefit, but may depend on exercise intensity. This study assessed the effects of exercise intensity on post-exercise arterial stiffness in older adults with varying fitness levels.


METHODS
Fifty-one older adults (72 ± 5 years) were stratified into fitness tertiles ([Formula: see text]O2peak: low-, 22.3 ± 3.1; mid-, 27.5 ± 2.4 and high-fit 36.3 ± 6.5 mL kg-1 min-1). In a randomised order, participants underwent control (no-exercise), moderate-intensity continuous exercise (40% of peak power output; PPO), and higher-intensity interval exercise (70% of PPO) protocols. Pulse wave velocity (PWV), augmentation index (AIx75) and reflection magnitude (RM) were assessed at rest and during 90 min of recovery following each protocol.


RESULTS
After control, delta PWV increased over time (P < 0.001) and delta RM was unchanged. After higher-intensity interval exercise, delta PWV (P < 0.001) and delta RM (P < 0.001) were lower to control in all fitness groups. After moderate-intensity continuous exercise, delta PWV was not different from control in low-fit adults (P = 0.057), but was lower in the mid- and higher-fit older adults. Post-exercise AIx75 was higher to control in all fitness groups (P = 0.001).


CONCLUSIONS
In older adults, PWV increases during seated rest and this response is attenuated after higher-intensity interval exercise, regardless of fitness level. This attenuation was also observed after moderate-intensity continuous exercise in adults with higher, but not lower fitness levels. Submaximal exercise reveals differences in the arterial stiffness responses between older adults with higher and lower cardiorespiratory fitness.
['Perissiou|Maria|M|', 'Bailey|Tom G|TG|', 'Windsor|Mark|M|', 'Nam|Michael Chi Yuan|MCY|', 'Greaves|Kim|K|', 'Leicht|Anthony S|AS|', 'Golledge|Jonathan|J|', 'Askew|Christopher D|CD|http://orcid.org/0000-0001-8076-8789']
D000368:Aged D000369:Aged, 80 and over D000072599:Cardiorespiratory Fitness D005260:Female D006801:Humans D008297:Male D010101:Oxygen Consumption D064797:Physical Conditioning, Human D011897:Random Allocation D059289:Vascular Stiffness
Exercise intensity Ageing Pulse wave velocity Wave reflection characteristics