Role of hydration status on cognitive functioning in athletes: A scoping review

Abstract

The detrimental effects of dehydration on cognitive functioning have been researched; however, definitive conclusions were not extracted. Therefore, the present review aimed to examine the role of hydration status and its influence on cognitive functioning in athletes. Research studies were identified by searching online databases such as PubMed, Google Scholar and ProQuest using the keywords ‘hypohydration’, ‘dehydration’, ‘hydration’, ‘euhydration’, ‘cognition’, ‘cognitive performance’, ‘cognitive functioning’, ‘athletes’ and ‘sportspersons’. A total of 50 original studies were identified, and 24 articles that met the inclusion criteria were examined for the review. A decrease in cognitive functioning was reported in 12 studies with dehydration. This trend was particularly observed when dehydration was coupled with increased exercise duration and/or exercising in a hot environment or high-intensity exercise. Ten studies did not find any impact of dehydration or euhydration on cognitive functioning, and two studies showed increased attention and accuracy in dehydration. Cognitive functioning seems to be unaffected due to dehydration until there is an increased exercise intensity and/or duration in hot and humid conditions. Further studies high in the hierarchy are required to provide definitive conclusions due to limited scientific evidence, heterogeneity in the methodology and non-applicability of outcomes to both genders.