Pre- and Post-Race Hydration Status in Hyponatremic and Non-Hyponatremic Ultra-Endurance Athletes

Daniela Chlíbková ； Thomas Rosemann ； Lenka Posch ； Radek Matou□ek ； Beat Knechtle

《The Chinese Journal of Physiology》 59卷3期 (2016/06) Pp. 173-183

https://doi.org/10.4077/CJP.2016.BAE391

並列摘要

The monitoring of body mass (BM) plasma sodium concentration ([Na^+]) and urinary specific gravity (U_(sg)) are com-monly used to help detect and prevent over- or dehydration in endurance athletes. We investigated pre-and post-race hydration status in 113 amateur 24-h ultra-runners, 100-km ultra-runners, multi-stage mountain bikers and 24-h mountain bikers, which drank ad libitum without any intervention and compared results of hyponatremic and non-hyponatremic finishers. On average, pre-race plasma [Na^+] and both pre- and post-race levels of U_(sg) and BM were not significantly different between both groups. However, nearly 86% of the post-race hyponatremic (exercise-associated hyponatremia, EAH) and 68% of the normonatremic (non-EAH) ultra-athletes probably drank prior the race greater volumes than their thirst dictated regarding to individual prerace U_(sg) levels. Fluid intake during the race was equal and was not related to plasma [Na^+], U_(sg) or BM changes. A significant decrease in post-race plasma [Na^+], BM and an increasement in post-race U_(sg) was observed in EAH and non-EAH finishers. Moreover, pre-race plasma [Na^+] was inversely associated with post - race percentage change in p lasma [Na^+], and pre-race U_(sg) and urinary [Na+] with percentage change in U_(sg) in both groups with and without post-race EAH. Thirteen (11.5%) finishers developed post-race EAH (plasma [Na+] ＜ 135 mM). The incidence of EAH in ultra-endurance athletes competing in the Czech Republic was higher than reported previously.

並列關鍵字

mountain bikers ； plasma sodium ； runners ； urinary sodium

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