Responses to Moderate and Low Sodium Diets During Exercise-Heat Acclimation
Abstract
This investigation examined whether lo sodium (Na+) (LNA; 68 mEq Na+. d-1) or moderate Na+ (MNA; 137 mEq Na+.d-1) intake allowed humans to maintain health, exercise, and physiologic function during 10 days of prolonged exercise- heat acclimation (HA). Seventeen volunteers, ages 19 to 21, consumed either LNA (n=8) or MNA (n=9) during HA (41 deg C, 21% RH; treadmill walking for 30 min.h- 1, 8 h.d-1 at 5.6 km.h-1, 5% grade), which resulted in significantly reduced heart rate, rectal temperature, and urine Na+ for both groups. There were few between-diet differences in any variables measured. Mean plasma volume in LNA expanded significantly less than in MNA by Days 11 and 15, but reached the MNA level on Day 17 (+12.3 vs. +12.4%) . The absence of heat illness, the presence of normal physiologic responses, and the total distance walked indicated successful and similar HA with both levels of dietary Na+.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1993
- Accession Number
- ADA273292
Entities
People
- Catherine Obrien
- E. W. Askew
- Jane P. Deluca
- Lawrence E. Armstrong
- Roger W. Hubbard
Organizations
- United States Army Research Institute of Environmental Medicine