PURPOSE:to determine the strength of the association between the amount of fluid people say they want to drink after exercise and the actual amount of fluid intake within 30 min post-exercise.

METHODS:11 healthy males (1.77 ± 0.05 m, 71.64 ± 9.0 kg) completed a total of 27 sessions of stationary bike exercise at 75-85% HRmax in the heat (WBGT = 27.3 ± 1.2) to reach a dehydration of 1, 2, or 3% BM. Immediately before completing the exercise (D0), and 15 min after initiating rehydration (D15), participants chose from a real-life, 3D scale with 10 identical water-filled bottles (from 100 mL to 1000 mL), which one they would like to drink. Actual ad libitum water intake was recorded 15 min (I15) and 30 min (I30) post-exercise. Intake was completed in the same environment as the exercise.

RESULTS: Participants lost 1.42 kg (0.56 - 2.52 kg) and drank 1239 mL (490-1827 mL) of water (mean (range)). Water intake was different over time (p < 0.001) registering 966 (408 - 1445mL) and 274 (0 - 610mL) for I15 and I30, respectively. BM recovery was 86.5 ± 40.2% of BM loss. D0 was significantly associated with I30 (r = 0.47, p = 0.016) and with I15 (r = 0.61, p = 0.001). D15 was not significantly associated with I30 (r = -0.10, p = 0.627).

CONCLUSIONS: In the absence of fluid intake, the desire to drink water upon exercise termination is significantly associated with early actual drinking. However, the association weakens with time. The desire to drink water after some ingestion has taken place fails to drive further intake.