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Ad libitum fluid intakes and thermoregulatory responses of female distance runners in three environments.
J Sports Sci. 2001 Nov; 19(11):845-54.JS

Abstract

Ad libitum fluid intakes and thermoregulatory responses were compared in eight female marathon runners during a 30 km treadmill run at individual best marathon race pace (range = 2.45-4.07 m x s(-1)) under three wet bulb globe temperature conditions (25 degrees C, 17 degrees C and 12 degrees C, corresponding to hot, moderate and cool conditions, respectively). Rectal temperature, mean skin temperature and heart rate were recorded at 10 min intervals and expired air was collected every 5 km during exercise. Simulated water stations were also provided at 5 km intervals with voluntary fluid intake being recorded. Blood was drawn before and after exercise for the determination of plasma volume changes and osmolarity. Ad libitum fluid intakes in the hot trial (0.70+/-0.31 l x h(-1); mean+/-s) were greater (P< 0.05) than in the cool (0.47+/-0.13 l x h(-1)) but not the moderate (0.54+/-0.26 l x h(-1)) trial. Each volume replaced 63%, 68% and 73% of total sweat losses in each condition, respectively, and kept dehydration below approximately 3% of body mass. After the initial 30 min of exercise, rectal temperature was maintained well below 39 degrees C for > 2 h of continuous running. The results demonstrate that the thermoregulatory responses of female distance runners to exercise in variable, but compensable, weather conditions is well maintained when ad libitum fluid intakes replace approximately 60-70% of sweat losses.

Authors+Show Affiliations

US Army Research Institute of Environmental Medicine, Thermal and Mountain Medicine Division, Natick, MA 01760-5007, USA.No affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

11695506

Citation

Cheuvront, S N., and E M. Haymes. "Ad Libitum Fluid Intakes and Thermoregulatory Responses of Female Distance Runners in Three Environments." Journal of Sports Sciences, vol. 19, no. 11, 2001, pp. 845-54.
Cheuvront SN, Haymes EM. Ad libitum fluid intakes and thermoregulatory responses of female distance runners in three environments. J Sports Sci. 2001;19(11):845-54.
Cheuvront, S. N., & Haymes, E. M. (2001). Ad libitum fluid intakes and thermoregulatory responses of female distance runners in three environments. Journal of Sports Sciences, 19(11), 845-54.
Cheuvront SN, Haymes EM. Ad Libitum Fluid Intakes and Thermoregulatory Responses of Female Distance Runners in Three Environments. J Sports Sci. 2001;19(11):845-54. PubMed PMID: 11695506.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Ad libitum fluid intakes and thermoregulatory responses of female distance runners in three environments. AU - Cheuvront,S N, AU - Haymes,E M, PY - 2001/11/7/pubmed PY - 2002/3/1/medline PY - 2001/11/7/entrez SP - 845 EP - 54 JF - Journal of sports sciences JO - J Sports Sci VL - 19 IS - 11 N2 - Ad libitum fluid intakes and thermoregulatory responses were compared in eight female marathon runners during a 30 km treadmill run at individual best marathon race pace (range = 2.45-4.07 m x s(-1)) under three wet bulb globe temperature conditions (25 degrees C, 17 degrees C and 12 degrees C, corresponding to hot, moderate and cool conditions, respectively). Rectal temperature, mean skin temperature and heart rate were recorded at 10 min intervals and expired air was collected every 5 km during exercise. Simulated water stations were also provided at 5 km intervals with voluntary fluid intake being recorded. Blood was drawn before and after exercise for the determination of plasma volume changes and osmolarity. Ad libitum fluid intakes in the hot trial (0.70+/-0.31 l x h(-1); mean+/-s) were greater (P< 0.05) than in the cool (0.47+/-0.13 l x h(-1)) but not the moderate (0.54+/-0.26 l x h(-1)) trial. Each volume replaced 63%, 68% and 73% of total sweat losses in each condition, respectively, and kept dehydration below approximately 3% of body mass. After the initial 30 min of exercise, rectal temperature was maintained well below 39 degrees C for > 2 h of continuous running. The results demonstrate that the thermoregulatory responses of female distance runners to exercise in variable, but compensable, weather conditions is well maintained when ad libitum fluid intakes replace approximately 60-70% of sweat losses. SN - 0264-0414 UR - https://www.unboundmedicine.com/medline/citation/11695506/Ad_libitum_fluid_intakes_and_thermoregulatory_responses_of_female_distance_runners_in_three_environments_ L2 - https://www.tandfonline.com/doi/full/10.1080/026404101753113796 DB - PRIME DP - Unbound Medicine ER -