Maughan R J, Meyer N L
Loughborough University, Loughborough, UK.
Nestle Nutr Inst Workshop Ser. 2013;76:25-37. doi: 10.1159/000350225. Epub 2013 Jul 25.
Hydration status has profound effects on both physical and mental performance, and sports performance is thus critically affected. Both overhydration and underhydration - if sufficiently severe - will impair performance and pose a risk to health. Athletes may begin exercise in a hypohydrated state as a result of incomplete recovery from water loss induced in order to achieve a specific body mass target or due to incomplete recovery from a previous competition or training session. Dehydration will also develop in endurance exercise where fluid intake does not match water loss. The focus has generally been on training rather than on competition, but sweat loss and fluid replacement in training may have important implications. Hypohydration may impair training quality and may also increase stress levels. It is unclear whether this will have negative effects (reduced training quality, impaired immunity) or whether it will promote a greater adaptive response. Hypohydration and the consequent hyperthermia, however, can enhance the effectiveness of a heat acclimation program, resulting in improved endurance performance in warm and temperate environments. Drinking in training may be important in enhancing tolerance of the gut when athletes plan to drink in competition. The distribution of water between body water compartments may also be important in the initiation and promotion of cellular adaptations to the training stimulus.
水合状态对身体和心理表现都有深远影响，因此运动表现也会受到严重影响。过度水合和水合不足——如果足够严重的话——都会损害表现并对健康构成风险。运动员可能由于为达到特定体重目标而导致的水分流失未完全恢复，或者由于之前比赛或训练课的恢复不完全，而在轻度缺水状态下开始运动。在耐力运动中，如果液体摄入量与失水量不匹配，也会出现脱水。人们通常将重点放在训练而非比赛上，但训练中的出汗量和液体补充可能具有重要意义。轻度缺水可能会损害训练质量，还可能增加压力水平。目前尚不清楚这是否会产生负面影响（训练质量下降、免疫力受损），或者它是否会促进更大的适应性反应。然而，轻度缺水以及随之而来的体温过高，可以提高热适应计划的效果，从而在温暖和温带环境中提高耐力表现。当运动员计划在比赛中饮水时，训练中的饮水对于增强肠道耐受性可能很重要。身体水分隔室之间的水分分布在引发和促进细胞对训练刺激的适应方面也可能很重要。
