Expanded Prediction Equations of Human Sweat Loss and Water Needs
Abstract
The Institute of Medicine expressed a need for improved sweating rate (m'sw) prediction models that calculate hourly and daily water needs based on metabolic rate, clothing, and environment. More than 25 years ago, the original Shapiro prediction equation (OSE) was formulated as m'sw (g*m-2*h-11) +27.9 Ereq*(Emax-)0.455, where Ereq is required evaporative heat loss and Emax is maximum evaporative power of the environment; OSE was developed for a limited set of environments, exposures times, and clothing systems. Recent evidence shows that OSE often overpredicts fluid needs. Our study developed a corrected OSE and a new m'sw prediction equation by using independent data sets from a wide range of environmental conditions, metabolic rates (rest to <450 W/m2), and variable exercise durations. Whole body sweat losses were carefully measured in 101 volunteers (80 males and 21 females; >500 observations) by using a variety of metabolic rates over a range of environmental conditions (ambient temperature, 15-46 deg C; water vapor pressure, 0.27-4.45 kPa; wind speed, 0.4-2.5 m/s), clothing, and equipment combinations and durations (2-8 h). Data are expressed as grams per square meter per hour and were analyzed using fuzzy piecewise regression.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2009
- Accession Number
- ADA506525
Entities
People
- D. A. Goodman
- L. A. Blanchard
- L. G. Berglund
- Michael N. Sawka
- R. R. Gonzalez
- S. J. Montain
- S. N. Cheuvront
Organizations
- United States Army Research Institute of Environmental Medicine