Perception of drinking water temperature and effects for humans after exercise.

Subjects rated the perceived temperature and hedonic values of four samples of drinking water (5 degrees, 16 degrees, 22 degrees, 38 degrees C) after exercise and on a control day. Ad lib drinking of any of the four samples was permitted for 20 minutes after exercise and intake was measured. Subjects completed questionnaires pertaining to their subjective states. Sensory thermal neutral water was found to be close to 22 degrees C which was also judged to be affectively neutral. Subjects rated 16 degrees C water higher on the hedonic scale after exercise than they did on a control day, despite the fact that no change in the perception of this temperature was observed. Responses to the symptoms questionnaire showed a marked effect of exercise on the perception of thirst, sweating, body warmth and dryness in the mouth. Sensations of stomach fullness could not account for the incomplete rehydration of most subjects in the time allotted. It was suggested that a rapid reduction in symptoms which initiate drinking was responsible for drinking termination. The role of water temperature in the reduction of thirst symptoms was discussed.