Effectiveness of glycerol as a rehydrating agent.
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.
Department of Physical Education, Western Illinois University, Macomb, IL 61455, USA.
T P
TP
Scheett
M J
MJ
Webster
K D
KD
Wagoner
D000328:Adult; D001810:Blood Volume; D001834:Body Water / Q000502:physiology*; D003681:Dehydration / Q000517:prevention & control / Q000628:therapy*; D015444:Exercise / Q000502:physiology; D005990:Glycerol / Q000008:administration & dosage*; D006358:Hot Temperature; D006801:Humans; D008297:Male; D015532:Rehydration Solutions / Q000008:administration & dosage*; D013997:Time Factors
D015532:Rehydration Solutions; D005990:Glycerol