Galloway S D
Department of Sports Studies, University of Stirling, Stirling FK9 4LA Scotland.
Can J Appl Physiol. 1999 Apr;24(2):188-200. doi: 10.1139/h99-016.
Exercise capacity and exercise performance are reduced when the ambient temperature is high. This has mainly been attributed to the large sweat losses which lead to hypohydration, a failure of thermoregulation, and eventually circulatory collapse. Exercising athletes rarely drink enough before or during exercise to replace the ongoing fluid losses, especially in hot conditions. In order to combat dehydration, hyperthermia, and impending circulatory collapse, athletes should drink fluids before, during, and after exercise. Preexercise strategies include attempts to maintain euhydration but also to hyperhydrate. Hyperhydration is relatively easy to achieve, but thermoregulatory benefits during prolonged exercise have not been observed in comparison to euhydration. In prolonged continuous exercise, fluid and carbohydrate (CHO) ingestion has clearly been shown to improve performance, but the evidence is not so clear for high-intensity intermittent exercise over a prolonged period. The general consensus is that fluid ingestion should match sweat losses during exercise and that the drink should contain CHO and electrolytes to assist water transport in the intestine and to improve palatability. Postexercise rehydration is essential when the strategies adopted before or during exercise have not been effective. The best postexercise rehydration strategy would be to ingest a large volume of a beverage that contains a CHO source and a high sodium content.
当环境温度较高时，运动能力和运动表现会下降。这主要归因于大量出汗导致的水分流失，进而引发低水合状态、体温调节功能失效，最终导致循环衰竭。运动的运动员在运动前或运动期间很少饮用足够的液体来补充持续的水分流失，尤其是在炎热条件下。为了对抗脱水、体温过高和即将发生的循环衰竭，运动员应在运动前、运动期间和运动后饮用液体。运动前的策略包括试图维持正常水合状态，同时也进行过度水合。过度水合相对容易实现，但与正常水合相比，在长时间运动期间尚未观察到体温调节方面的益处。在长时间持续运动中，摄入液体和碳水化合物（CHO）已明确显示可提高运动表现，但对于长时间高强度间歇运动，证据并不那么明确。普遍的共识是，运动期间液体摄入应与出汗量相匹配，并且饮料应含有CHO和电解质，以协助肠道内的水分运输并改善口感。当运动前或运动期间采取的策略无效时，运动后补液至关重要。最佳的运动后补液策略是摄入大量含有CHO来源和高钠含量的饮料。
