McCartney Danielle, Desbrow Ben, Irwin Christopher
School of Allied Health Sciences and Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia.
Sports Med Open. 2017 Dec;3(1):13. doi: 10.1186/s40798-017-0079-y. Epub 2017 Mar 18.
The deleterious effects of dehydration on athletic and cognitive performance have been well documented. As such, dehydrated individuals are advised to consume fluid in volumes equivalent to 1.25 to 1.5 L kg body mass (BM) lost to restore body water content. However, individuals undertaking subsequent activity may have limited time to consume fluid. Within this context, the impact of fluid intake practices is unclear. This systematic review investigated the effect of fluid consumption following a period of dehydration on subsequent athletic and cognitive performance.
PubMed (MEDLINE), Web of Science (via Thomas Reuters) and Scopus databases were searched for articles reporting on athletic (categorized as: continuous, intermittent, resistance, sport-specific and balance exercise) or cognitive performance following dehydration of participants under control (no fluid) and intervention (fluid intake) conditions. Meta-analytic procedures determined intervention efficacy for continuous exercise performance.
Sixty-four trials (n = 643 participants) derived from 42 publications were reviewed. Dehydration decreased BM by 1.3-4.2%, and fluid intake was equivalent to 0.4-1.55 L kg BM lost. Fluid intake significantly improved continuous exercise performance (22 trials), Hedges' g = 0.46, 95% CI 0.32, 0.61. Improvement was greatest when exercise was performed in hotter environments and over longer durations. The volume or timing of fluid consumption did not influence the magnitude of this effect. Evidence indicating a benefit of fluid intake on intermittent (10 trials), resistance (9 trials), sport-specific (6 trials) and balance (2 trials) exercise and on cognitive performance (15 trials) was less apparent and requires further elucidation.
Fluid consumption following dehydration may improve continuous exercise performance under heat stress conditions, even when the body water deficit is modest and fluid intake is inadequate for complete rehydration.
脱水对运动和认知表现的有害影响已有充分记录。因此，建议脱水个体饮用相当于每千克体重损失1.25至1.5升的液体，以恢复身体水分含量。然而，进行后续活动的个体可能饮用液体的时间有限。在此背景下，液体摄入方式的影响尚不清楚。本系统评价研究了脱水一段时间后饮用液体对后续运动和认知表现的影响。
在PubMed（MEDLINE）、科学网（通过汤森路透）和Scopus数据库中检索文章，这些文章报告了在对照（无液体摄入）和干预（液体摄入）条件下参与者脱水后的运动表现（分为：持续运动、间歇运动、阻力运动、特定运动和平衡运动）或认知表现。荟萃分析程序确定了持续运动表现的干预效果。
对来自42篇出版物的64项试验（n = 643名参与者）进行了综述。脱水使体重下降1.3 - 4.2%，液体摄入量相当于每千克体重损失的0.4 - 1.55升。液体摄入显著改善了持续运动表现（22项试验），Hedges' g = 0.46，95%置信区间0.32, 0.61。在温度较高的环境中进行较长时间运动时，改善最为明显。液体摄入的量或时间并不影响这种效果的大小。表明液体摄入对间歇运动（10项试验）、阻力运动（9项试验）、特定运动（6项试验）和平衡运动（2项试验）以及认知表现（15项试验）有益的证据不太明显，需要进一步阐明。
脱水后饮用液体可能会改善热应激条件下的持续运动表现，即使身体水分亏缺较小且液体摄入量不足以完全补水。
