The influence of exercise on vascular and cognitive function in healthy ageing

This thesis aimed to investigate the influence of acute and chronic exercise on vascular andcognitive function in healthy older adults and to elucidate potential associations betweenvascular and cognitive health with ageing and exercise. The first study of this thesis consistedof a systematic review and meta-analysis which found that long-term endurance trained healthyolder adults exhibit superior brachial artery flow mediated dilation (FMD) compared tosedentary cohorts (mean difference (MD): 2.1 %; P < 0.001). However, periods of short-termendurance training did not improve BA FMD (MD: 0.7%; P = 0.316). Conversely, in study 2,masters athletes did not exhibit superior brachial artery FMD (MD: -0.38 %; P = 0.978), carotidartery (CA) intima media thickness (MD: 0.006 mm; P = 0.993), or blood flow (common CAMD: -110.9 ml.min-1; P = 0.129; internal CA MD: -65.7 ml.min-1; P = 0.502) compared toolder recreationally active adults. Additionally, the recreationally active group demonstratedbetter memory performance during one cognitive test (MD: 5.2 errors; P = 0.003). Minimaldifferences in vascular and cognitive function were also observed between the older and youngcontrol groups (P < 0.05). Study 3 focused specifically on the vascular and cognitive functionof healthy middle-aged physically active and inactive females. Whilst no differences inbrachial artery FMD were observed (MD: 0.4 %; P = 0.762), the active females demonstratedsuperior CA compliance when compared with their inactive counterparts (peak circumferentialstrain MD: 1.9 %; P = 0.003; peak strain rate MD: 0.133 s-1; P = 0.004). However, the inactivegroup performed better in one test of executive function compared to the active females (animalfluency MD: 6 words; P = 0.002). Finally, 12 weeks of resistance training improved theinformation processing speed of the previously inactive middle-aged females during Study 4(Trail A MD: 2 s; P = 0.047; Stroop 1 MD: 0.4 s; P = 0.014; Stroop 3 MD: 0.7 s; P = 0.031).CA compliance was improved at the P < 0.05 level when assessed during and immediatelyafter physiological stress (peak circumferential strain MD: 0.7 %; P = 0.012). However, noassociations were observed between improved CA and cognitive function within the healthymiddle-aged cohort at the P < 0.05 level. Overall, the findings from this thesis may suggestthat long-term endurance and short-term resistance training may have selective benefits forarterial health with ageing, in which some benefits may only be observed when individuals areexposed to physiological stress. Moreover, cognitive function was positively influenced byshort-term resistance, but not long-term endurance exercise. However, it appears thatimprovements in cognitive function from resistance exercise may not be mediated throughsimultaneous improvements in extra-cranial vascular function in healthy middle-aged females.Additional research is needed to further investigate potential links between vascular andcognitive function with exercise in ageing.