Voluntary Dehydration and Alliesthesia for Water,
Abstract
The purpose of this experiment was to explore the complex relationship between fluid consumption and consumption factors (thirst, voluntary dehydration, water alliesthesia, palatability, work-rest cycle) during a simulated, 14.5 km (9 mile), desert walk (treadmill, 1.34 m/sec (3.0 mph), 5% grade, 40 C d.b./26 C w.b. and wind speed of 2.5 mph). Twenty-nine Ss were tested (30 min/h, 6 h) on each of two nonconsecutive days. Ss were randomly assigned to 1 of 3 groups: tap water (n=8), iodine-treated tap water (n=11) or iodine-treated, flavored tap water (n=10). The temperature of the water was 40 C during one trial and 15 C on the other. Mean sweat losses (6 h) were similar and averaged 3.9 + or - 0.06 kg. Fluid consumption (6 h) varied between 1.4 kg (warm, iodine-treated; 232 + or - 44 g/h) and 3.0 kg (cool, iodine-treated, flavored; 509 + or - 50 g/h). Warm drinks were consumed at a lower rate than cool drinks (negative and positive alliesthesia). This decreased consumption resulted in the highest percent body weight losses (2.8 and 3.2%). Cooling and flavoring effects o consumption were additive and increased the rate of intake by 120%. The apparent paradox between reduced consumption concomitant with severe dehydration and hyperthermia is attributed to negative alliesthesia for warm water rather than an apparent inadequacy of the thirst mechanism. The reluctance to drink warm, iodine-treated water resulted in significant hyperthermia, dehydration, hypovolemia and in two cases, heat illness.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 13, 1983
- Accession Number
- ADA129122
Entities
People
- B. Sandick
- M. Durkot
- R. Francesconi
- R. Hubbard
- W. Matthew
Organizations
- United States Army Research Institute of Environmental Medicine