PURPOSE: To determine whether chicken noodle soup before exercise increases ad libitum water intake, fluid balance, and physical and cognitive performance compared with water. METHODS: Nine trained men (age: 25±3y; VO2peak: 54.2±5.1ml·kg-1·min-1; mean±SD) performed cycle exercise in the heat (Wet Bulb Globe Temperature=25.9±0.4ºC) for 90min at 50% VO2peak, 45min after ingesting 355ml of either commercially-available bottled water (WATER) or chicken noodle soup (SOUP). The same bottled water was allowed ad libitum throughout both trials. Participants then completed a time trial to finish a given amount of work (10min at 90% VO2peak; n=8). Cognitive performance was evaluated by the Stroop Word/Color task before, every 30 min during, and immediately after the time trial. RESULTS: Ad libitum water intake throughout steady-state exercise (1435±593 vs. 1163±427g, resp.; P<0.03) was greater in SOUP compared with WATER. Total urine volume was similar in both trials (P=0.13) resulting in a trend for greater water retention in SOUP compared with WATER (87.7±7.6 vs. 74.9±21.7%, resp.; P=0.09) possibly due to a change in free water clearance (-0.32±1.22 vs. 0.51±1.06mL/min, resp; P=0.07). Fluid balance tended to be improved with SOUP (-106±603 vs. -478±594g, P=0.05). Likewise, change in plasma volume tended to be reduced in SOUP compared with WATER (P=0.06). Only mild dehydration was achieved (<1%) and physical performance was not different between treatments (P=0.77). The number of errors in the Stroop word/color task was lower in SOUP throughout the entire trial (treatment effect; P=0.04). CONCLUSION: SOUP before exercise increased ad libitum water intake and may alter kidney function.nhttp://www.ncbi.nlm.nih.gov/pubmed/23239679