Fluid Balance in Team Sport Athletes and the Effect of Hypohydration on Cognitive, Technical, and Physical Performance.
Level 5 - mechanism / opinion, no new human data
Narrative review without systematic methodology or meta-analysis
PubMed 28508338 · doi:10.1007/s40279-017-0738-7
What was done
This narrative review synthesized literature describing sweat losses and fluid balance changes in team sport athletes (such as soccer, American football, rugby, basketball, tennis, and ice hockey) and examined the impact of hypohydration on cognitive, technical, and physical performance (principally in soccer, basketball, cricket, and baseball), alongside potential underlying mechanisms.
What was found
Significant hypohydration (mean body mass loss [BML] >2%) was reported most consistently in soccer. American football, rugby, basketball, tennis, and ice hockey reported high sweating rates but generally mild fluid disturbances (mean BML <2%). Across soccer, basketball, cricket, and baseball, performance effects were mixed, with impairments typically occurring at higher dehydration levels (3–4% BML) and when dehydration involved heat stress. Hypohydration consistently coincided with higher ratings of perceived exertion and subjective fatigue.
Why it matters
This review clarifies that while sweat rates are high across team sports, performance impairments from hypohydration primarily emerge at higher fluid deficits (3–4% BML) or under thermal strain, driven in part by heightened perceived exertion.
Limits
The review is narrative rather than systematic, with no quantitative meta-analysis or study count reported in the abstract. Findings across sports remain mixed, and the broader literature is limited by a lack of standardized sport-specific testing protocols and sparse data on modifying factors such as sex, age, or athlete caliber.
Cited by
- context Even a slight degree of dehydration can diminish cognitive and physical performance.