Fluid tolerance while running: effect of repeated trials.
This study assessed tolerance to fluid ingestion with repeated sessions of drinking while running. Runners (n = 7; age 22 +/- 2 yr; V O (2max) = 54.4 +/- 7.1 ml/kg/min) performed six 90-min runs (65 % V O (2max); separated by 7 - 11 days). During run 1, subjects drank a glucose-electrolyte solution AD LIBITUM for 1 min every 10 min. During runs 2 - 6, subjects drank a volume of the solution every 10 min equal to their sweat production over 10 min during run 1. Stomach comfort (1 - 4 scale) and gastrointestinal symptoms were also assessed every 10 min. Gastric emptying rate was determined in runs 2 and 6. Subjects consumed more (p < 0.05) fluid during runs 2 - 6 (mean +/- SD; 1247 +/- 162 ml), than during run 1 (508 +/- 476 ml). Stomach comfort improved (p < 0.05) on runs 5 and 6 (1.7 +/- 0.5 mean ranks) compared to run 2 (2.3 +/- 0.5 mean ranks). Gastric emptying rate was not different between runs 2 and 6 (12.0 +/- 1.9 ml/min vs. 12.3 +/- 2.3 ml/min, respectively). These results indicate repeated sessions of drinking at a rate matching sweat rate improves stomach comfort, however, gastric emptying rate does not change under such conditions.
Department of Exercise Science, Creighton University, Omaha, Nebraska 68178, United States. plambert@creighton.edu
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Lambert
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Lang
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Bull
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Eckerson
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Lanspa
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J
O'Brien
D000328:Adult; D004573:Electrolytes; D005260:Female; D005440:Fluid Therapy; D005746:Gastric Emptying; D006801:Humans; D007552:Isotonic Solutions; D008297:Male; D010101:Oxygen Consumption; D015532:Rehydration Solutions / Q000008:administration & dosage; D012420:Running / Q000502:physiology*; D013546:Sweating; D014882:Water-Electrolyte Balance / Q000502:physiology*
D004573:Electrolytes; D007552:Isotonic Solutions; D015532:Rehydration Solutions