Neural Efficiency and Sensorimotor Adaptations in Swimming Athletes: A Systematic Review of Neuroimaging and Cognitive-Behavioral Evidence for Performance and Wellbeing.
Level 4 - case-series / case-control
Systematic review of predominantly cross-sectional observational and small mechanistic studies
PubMed 41594837 · doi:10.3390/brainsci16010116
What was done
A systematic review following PRISMA 2020 guidelines searched seven databases (1999–2024) for studies evaluating cognitive performance and neural adaptations in swimmers compared to non-athletes or across skill levels. Twenty-four studies met inclusion criteria: 9 neuroimaging studies (EEG: n = 4, fMRI: n = 2, ERP: n = 2, TMS: n = 1) and 15 behavioral studies. Study quality and risk of bias were evaluated using adapted Cochrane RoB2 and Newcastle-Ottawa Scale tools.
What was found
Elite swimmers showed sparser upper beta connectivity (35% fewer connections, d = 0.76, p = 0.040) and enhanced alpha rhythm intensity (p <= 0.01). Swimming expertise correlated with superior attention, working memory, and executive control (d = 0.69–1.31), with thalamo-sensorimotor functional connectivity accounting for 41% of world ranking variance (r^2 = 0.41, p < 0.001). External focus strategies improved performance in intermediate swimmers but yielded inconsistent effects in experts. Mental fatigue caused a 1.2% performance decrement in young adult swimmers (d = 0.13) but no significant impairment in master swimmers (p = 0.49). The COMT Val158Met polymorphism was associated with performance differences (p = 0.026). Reported effect sizes ranged from Cohen's d = 0.13 to 1.31.
Why it matters
This review synthesizes the neuroimaging and behavioral literature on swimming, identifying potential neural efficiency and cognitive markers associated with athletic expertise.
Limits
Eighty-eight percent of included studies used cross-sectional designs, precluding causal inference. Sample sizes were small (median n = 36) and all studies were underpowered. The review lacked a spatially quantitative synthesis or brain visualization, and longitudinal validation is missing.