Effectiveness of glycerol as a rehydrating agent

• Published in: International journal of sport nutrition and exercise metabolism Vol. 11; no. 1; p. 63
• Main Authors: Scheett, T P, Webster, M J, Wagoner, K D
• Format: Journal Article
• Language: English
• Published: United States 01.03.2001
• Subjects: Adult; Blood Volume; Body Water - physiology; Dehydration - prevention & control; Dehydration - therapy; Exercise - physiology; Glycerol - administration & dosage; Hot Temperature; Humans; Male; Rehydration Solutions - administration & dosage; Time Factors
• ISSN: 1526-484X; 1543-2742
• DOI: 10.1123/ijsnem.11.1.63

On two occasions, 8 male subjects completed a dehydration protocol, immediately followed by a 180-min rehydration protocol, then a subsequent exercise bout. During each dehydration session, subjects lost 3.1 +/- 0.4% body weight (BW) following discontinuous exercise in the heat (40 degreesC, 33% rh). During the first 30 min of rehydration, subjects ingested either 1.0-g glycerol x kg body weight(-1) + 30% of the total rehydration water volume (GLY), or 30% of the total rehydration water volume without glycerol (CON). The five remaining ingestions (every 30 min) were equal to 14% of the remaining fluid volume and were identical in nature. Fluid volume ingested equaled fluid volume lost during dehydration. Following the 180 min rehydration period, subjects cycled (appoximately 50% VO2 peak) in the heat (40 degrees C, 33% rh) until volitional exhaustion. Three observations were made: (a) Following glycerol-induced rehydration, time to volitional exhaustion was greater during the subsequent exercise bout in the heat (CON: 38.0 +/- 2.0, GLY 42.8 +/- 1.0 min, p <.05); (b) glycerol-induced rehydration significantly increased plasma volume restoration within 60 min and at the end of the 180-min rehydration period; and (c) total urine volume was lower and percent rehydration was greater following GLY, but neither was significantly different.