Cardiorespiratory fitness modulates the acute flow-mediated dilation response following high-intensity but not moderate-intensity exercise in elderly men

Abstract

39Impaired endothelial function is observed with ageing and with low cardiorespiratory fitness 40 (VO 2peak ) whilst improvements in both are suggested to be reliant on higher-intensity exercise in 41 the elderly. This may be due to the flow-mediated dilation (FMD)

Brachial artery endothelial function is unchanged after acute sprint interval exercise in sedentary men and women

“…Furthermore, while it may appear that scaled FMD increased by 0.9% from baseline to 24 h post‐exercise in men, examining the individual participant responses revealed that only two men were driving this change. Our findings are in contrast to previous reports that endothelial function increases between 1 and 24 h post‐exercise before returning to baseline levels by 24–48 h (Dawson et al., ) and to previously observed increases of 1–8% in endothelial function after higher‐volume interval protocols (Bailey et al., ; Bond et al., ; Chuensiri et al., ; Francois et al., ). Increases in brachial artery FMD of 1–1.5% have been deemed clinically and physiologically relevant (Inaba et al., ; Tinken et al., ).…”

“…Although acute increases in brachial FMD have been previously observed with interval exercise (Bailey et al, 2017;Bond et al, 2015;Chuensiri et al, 2015;Currie et al, 2012;Francois et al, 2016), these exercise paradigms involved longer intervals at submaximal intensities An unanticipated finding in this study was the observation of a slight attenuation in some resting and RH haemodynamic parameters at 1 h post-exercise. While SR AUC remained unchanged and time to peak dilatation tended to be longer at 1 h post-exercise, the attenuations in BF (resting BF, peak RH BF, and postdeflation BF averaged to the peak RH diameter) and MBV all seem to suggest that we may have captured the tail end of haemodynamic recovery.…”

“…Although acute increases in brachial FMD have been previously observed with interval exercise (Bailey et al., ; Bond et al., ; Chuensiri et al, ; Currie et al., ; Francois et al., ), these exercise paradigms involved longer intervals at submaximal intensities (12 × 1 min at 70% PPO, 10 × 1 min at 80% PPO, 8 × 1 min at 90% PPO, 7 × 1 min at 85% PPO, 8 × 20 s at 170% PPO), whereas the current study utilized a low‐volume model involving only 3 × 20 s supramaximal sprints. How this SIT model influences the brachial artery shear profile and what the minimum shear stimulus required to generate acute and lasting increases in endothelial function are both unknown.…”

“…Our findings suggest this low-volume protocol may not be sufficient to induce functional changes in the brachial artery of sedentary, but otherwise healthy adults. been observed after a 12 × 1 min (Bailey et al, 2017), 10 × 1 min (Currie, McKelvie, & MacDonald, 2012), 8 × 1 min (Bond, Hind, Williams, & Barker, 2015) and 7 × 1 min (Francois, Durrer, Pistawka, Halperin, & Little, 2016) protocol. The lowest volume model for which the acute brachial FMD response has been investigated involved 8 × 20 s cycling sprints and observed increases in brachial FMD immediately after exercise, but a 1 h assessment was not included (Chuensiri, Tanaka, & Suksom, 2015).…”

“…Dawson, Green, Cable, and Thijssen () have proposed a time course for the acute post‐exercise FMD response, whereby it is attenuated immediately after exercise, increases between 1 and 24 h, and returns to pre‐exercise levels by 24–48 h. Since the immediate post‐exercise response may be confounded by changes in sympathetic activity, the shear stimulus and/or arterial diameter (Padilla, Harris, & Wallace, ), 1 h post‐exercise is a common time for assessing the acute FMD response. At 1 h post‐exercise, increases in absolute or relative brachial FMD, of approximately 1–3% for relative FMD, have been observed after a 12 × 1 min (Bailey et al., ), 10 × 1 min (Currie, McKelvie, & MacDonald, ), 8 × 1 min (Bond, Hind, Williams, & Barker, ) and 7 × 1 min (Francois, Durrer, Pistawka, Halperin, & Little, ) protocol. The lowest volume model for which the acute brachial FMD response has been investigated involved 8 × 20 s cycling sprints and observed increases in brachial FMD immediately after exercise, but a 1 h assessment was not included (Chuensiri, Tanaka, & Suksom, ).…”