PRE- AND POST-RACE HYDRATION STATUS IN HYPONATREMIC AND NON-HYPONATREMIC ULTRA-ENDURANCE ATHLETES

PRE- AND POST-RACE HYDRATION STATUS IN HYPONATREMIC AND NON-HYPONATREMIC ULTRA-ENDURANCE ATHLETES

WoS Article

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 pre race 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 plasma [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.

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 pre race 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 plasma [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.

mountain bikers, plasma sodium, runners, urinary sodium

mountain bikers, plasma sodium, runners, urinary sodium

CHLÍBKOVÁ, D.; ROSEMANN, T.; POSCH, L.; MATOUŠEK, R.; KNECHTLE, B.

2017

30.06.2016

Chinese Journal of Physiology

Taiwan, Republic of China

0304-4920

CHINESE JOURNAL OF PHYSIOLOGY

59

3

Taiwan

173

183

11

https://pdfs.semanticscholar.org/f21e/34d6f36d6b891672280ccc4ef3ece0b2ec17.pdf