Search National Agricultural Library Digital Collections

NALDC Record Details:

Effect of heat acclimation on sweat minerals

Permanent URL:
http://handle.nal.usda.gov/10113/46852
File:
Download [PDF File]
Abstract:
Purpose: This study examined the impact of 10 d of exercise-heat acclimation on sweat mineral concentrations. Methods: Eight male subjects walked on a treadmill at 3.5 mph, 4% grade for 100 continuous minutes or until rectal temperature reached 39.5°C on 10 consecutive days in an environmental chamber set at 45°C, 20% relative humidity. Arm sweat samples were collected during the first 30 min of exercise-heat stress on days 1 and 10 using a polyethylene arm glove. Results: Final core temperature and HR values were significantly lower (P < 0.05) on day 10 versus day 1. Whole-body sweating rates increased by approximately 6% (P = 0.12). Sweat sodium concentration on day 10 (36.22 ± 7.22 mM) was significantly lower than day 1 (54.49 ± 16.18 mM) (P < 0.05). Sweat mineral concentrations of calcium (~29%), copper (~50%), and magnesium (~43%) were also significantly lower on day 10 versus day 1 of heat acclimation (P < 0.05). A trend for lower sweat iron (~75%; P = 0.07) and zinc (~23%; P = 0.10) concentrations were observed from day 1 to day 10. The estimated hourly sweat mineral losses (arm concentration x whole-body sweat rate) were reduced for calcium (~27%), copper (~46%), and magnesium (~42%) (P < 0.05), but not iron (75%) or zinc (~16%) (P > 0.05), from day 1 to day 10. Conclusion: Exercise-heat acclimation conserves arm sweat mineral concentrations and possibly whole-body sweat losses of calcium, copper, and magnesium, and may reduce sweat iron and zinc concentrations.
Author(s):
Chinevere, Troy D. , Kenefick, Robert W. , Cheuvront, Samuel N. , Lukaski, Henry C. , Sawka, Michael N.
Subject(s):
exercise , sweating , sweat , acclimation , heat , men , mineral content , rectum , body temperature , nutritional status , calcium , copper , magnesium , iron , zinc , blood serum
Format:
p. 886-891.
Note:
Includes references
Source:
Medicine & science in sports & exercise 2008 May, v. 40, no. 5
Language:
English
Year:
2008
Collection:
Journal Articles, USDA Authors, Peer-Reviewed
Rights:
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.