Body temperature responses to exercise in man on restricted food and water intake.

Abstract

Rectal temperatures (TR) of 12 clinically healthy soldiers were measured in a room at 25.5°C and 40–45% relative humidity during a 1-hour walk on a motor driven treadmill at 3.5 mph and 10% grade, during control with adequate food intake and water ad libitum, and during a period of food and water restriction. The daily water intake during the water restriction period was 900 ml for six of the men, Low Water group (L.W.), and 1800 ml for the other six, High Water group (H.W.). The restriction of water began at the same time as the restriction of food and lasted 5 full days for the L.W. group and 10 full days for the H.W. group. Food was restricted to 1000 calories from carbohydrate, 4.5 gm of NaCl and a multivitamin pill/day for 16 days. Water ad libitum was given throughout the experiment except for the period of water restriction. The L.W. group showed a progressive increase of TR at the end of the walk during the water restriction period with average TR 1.51℃, higher at peak dehydration than in control. In the H.W. group the greatest average increase, 0.46℃, was observed on day 5 of restriction. Administration of water ad libitum brought the work TR back to the control level in the L.W. group, but failed to produce any important change in the H.W. group. The relationship between dehydration, elevation of TR during work and changes in sweat rate is discussed. Submitted on July 24, 1958