Skip to main content
main-content

28.09.2018 | Original Article | Ausgabe 12/2018

European Journal of Applied Physiology 12/2018

Ad libitum drinking adequately supports hydration during 2 h of running in different ambient temperatures

Zeitschrift:
European Journal of Applied Physiology > Ausgabe 12/2018
Autoren:
Martin D. Hoffman, Rhiannon M. J. Snipe, Ricardo J. S. Costa
Wichtige Hinweise
Communicated by Narihiko Kondo.

Abstract

Purpose

To examine if ad libitum drinking will adequately support hydration during exertional heat stress.

Methods

Ten endurance-trained runners ran for 2 h at 60% of maximum oxygen uptake under different conditions. Participants drank water ad libitum during separate trials at mean ambient temperatures of 22 °C, 30 °C and 35 °C. Participants also completed three trials at a mean ambient temperature of 35 °C while drinking water ad libitum in all trials, and with consumption of programmed glucose or whey protein hydrolysate solutions to maintain euhydration in two of these trials. Heart rate, oxygen uptake, rectal temperature, perceived effort, and thermal sensation were monitored, and nude body mass, hemoglobin, hematocrit, and plasma osmolality were measured before and after exercise. Water and mass balance equations were used to calculate hydration-related variables.

Results

Participants adjusted their ad libitum water intake so that the same decrease in body mass (1.1–1.2 kg) and same decrease in body water (0.8–0.9 kg) were observed across the range of ambient temperatures which yielded significant differences (p < .001) in sweat loss. Overall, water intake and total water gain replaced 57% and 66% of the water loss, respectively. The loss in body mass and body water associated with ad libitum drinking resulted in no alteration in physiological and psychophysiological variables compared with the condition when hydration was nearly fully maintained (0.3 L body water deficit) relative to pre-exercise status from programmed drinking.

Conclusions

Ad libitum drinking is an appropriate strategy for supporting hydration during running for 2 h duration under hot conditions.

Bitte loggen Sie sich ein, um Zugang zu diesem Inhalt zu erhalten

★ PREMIUM-INHALT
e.Med Interdisziplinär

Mit e.Med Interdisziplinär erhalten Sie Zugang zu allen CME-Fortbildungen und Fachzeitschriften auf SpringerMedizin.de. Zusätzlich können Sie eine Zeitschrift Ihrer Wahl in gedruckter Form beziehen – ohne Aufpreis.

Jetzt e.Med zum Sonderpreis bestellen!

Weitere Produktempfehlungen anzeigen
Literatur
Über diesen Artikel

Weitere Artikel der Ausgabe 12/2018

European Journal of Applied Physiology 12/2018 Zur Ausgabe
  1. Sie können e.Med Allgemeinmedizin 14 Tage kostenlos testen (keine Print-Zeitschrift enthalten). Der Test läuft automatisch und formlos aus. Es kann nur einmal getestet werden.


 

Neu im Fachgebiet Arbeitsmedizin

Bildnachweise