Swimming‐related effects on cerebrovascular and cognitive function

Abstract

Both acute and regular exercise influence vascular and cognitive function. Upright aquatic exercise increases mean middle cerebral artery blood velocity (MCAvmean) and has been suggested as favorable for cerebrovascular adaptations. However, MCAvmean has not been reported during swimming. Thus, we examined the cerebrovascular and cognitive effects of swimming. Ten land‐based athletes (22 ± 5 years) and eight swimmers (19 ± 1 years) completed three cognitive tasks and four conditions that were used to independently and collectively delineate the swimming‐related factors (i.e., posture, immersion, CO2 retention [end‐tidal CO2; PETCO2], and motor involvement). Measurements of MCAvmean and PETCO2 were taken throughout each condition. Prone posture increased MCAvmean by 11% (P < 0.01 vs. upright land). Water immersion independently increased MCAvmean when upright (12%; P < 0.01) but not prone (P = 0.76). The consequent rise in PETCO2 during head‐out, breast‐stroke swimming (50% heart rate range) independently increased MCAvmean by 14% (P < 0.01), while the motor involvement of swimming per se did not significantly change MCAvmean (P = 0.32). While accounting for sex, swimmers had ~17% lower MCAvmean during all rest conditions (P ≤ 0.05). However, in a subset of participants, both groups had similar internal carotid artery diameters (P = 0.99) and velocities (P = 0.97). Water immersion per se did not alter cognition (P ≥ 0.15), but 20 min of moderate‐intensity swimming improved visuomotor performance by 4% (P = 0.03), regardless of athlete group (P = 0.12). In conclusion, breast‐stroke swimming increased MCAvmean mostly due to postural and PETCO2 effects, with minimal contributions from water immersion or motor activity. Lastly, swimming improved cognitive functioning acutely, regardless of athlete group. Future research should explore the chronic effects of swimming on cerebrovascular function and cognition, particularly in aging.

Indomethacin markedly blunts cerebral perfusion and reactivity, with little cognitive consequence in healthy young and older adults

“…Choice response time, inhibition and mental switching were tested using a response time battery consisting of Pro, Anti and Pro/Anti tasks, respectively (Shoemaker et al . (2019b), as well as based on (Guiney et al . 2015)).…”

“…Although an acute increase in perfusion does not measurably improve cognitive performance (Shoemaker et al . 2019 b ; Shoemaker et al . 2020), the extent to which cognition is resilient against lower cerebral perfusion is unknown.…”

Aquatic Therapy in Contemporary Neurorehabilitation: An Update

“…As detailed in the beginning of this article, cerebral blood flow is positively affected by immersion and aquatic exercise. [7][8][9] This increase in flow velocity stimulates endothelial nitric oxide synthase (eNOS), which promotes vascular compliance, improving oxygen delivery to brain tissues. There is an association between cerebral blood flow and dementia, although the relationship is complex and also related to cerebral metabolism.…”

“…In the study, Pugh and coworkers speculated that based upon their findings, water‐based exercise training may induce greater cerebrovascular health benefits than traditional land‐based exercise and that the therapeutic effect of this may be of significant health value. Although less relevant in rehabilitation practice, the question of cerebral blood flow during horizontal aquatic activity was addressed in a 2019 study of young adult recreational athletes and age‐matched swimmers, finding that although there was no significant difference between prone MCAv on land or in water, prone swimming (breaststroke) increased MCAv by nearly 50% 9 . Thus it appears that aquatic‐based activity has some potentially unique advantage in clinical matters where improvement in cerebral blood flow might be of rehabilitative value.…”

“…There are some potential physiologic reasons for the use of aquatic exercise programs in MCI and dementia. As detailed in the beginning of this article, cerebral blood flow is positively affected by immersion and aquatic exercise 7‐9 . This increase in flow velocity stimulates endothelial nitric oxide synthase (eNOS), which promotes vascular compliance, improving oxygen delivery to brain tissues.…”