title: Effect of drink flavor and NaCL on voluntary drinking and hydration in boys exercising in the heat.
abstract: This study was intended to assess the influence of drink flavor and composition on voluntary drinking and hydration status in children exercising intermittently at 35 +/- 1 degrees C and 45-50% relative humidity. Twelve boys (9-12 yr) performed three 3-h identical sessions (four 20-min cycling bouts at 50% maximal O2 uptake followed by 25-min rest). One of three beverages (chilled to 8-10 degrees C) was assigned to each session in a Latin-square sequence: unflavored water (W), grape-flavored water (FW), and grape-flavored water plus 6% carbohydrate and 18 mmol/l NaCl (CNa). Drinking was ad libitum. Body weight, heart rate, rectal and skin temperatures, and thirst and stomach fullness perceptions were monitored periodically. Total intake was 610, 882, and 1,157 g in W, FW, and CNa, respectively (CNa-W and CNa-FW; P < 0.05). Hypohydration was observed with W (-0.65% body wt) and FW (-0.32% body wt), but drinking CNa resulted in slight overhydration (+0.47% body wt, CNa-W, CNa-FW; P < 0.05). Other physiological and all perceptual variables were insignificantly different among trails. In conclusion, while flavoring of water reduces children's voluntary dehydration, further addition of 6% carbohydrates and 18 mmol/l NaCl prevents it altogether.
authors.affiliation: Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada.
authors.forename: B
authors.initials: B
authors.lastname: Wilk
authors.forename: O
authors.initials: O
authors.lastname: Bar-Or
mesh_terms: D001833:Body Temperature Regulation / Q000502:physiology*; D001835:Body Weight / Q000502:physiology*; D002648:Child; D004326:Drinking / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology; D006358:Hot Temperature; D006801:Humans; D008297:Male; D013649:Taste / Q000502:physiology*; D013997:Time Factors