Effects of ingesting a large volume of carbohydrate-electrolyte solution on rehydration during recovery and subsequent exercise capacity.
This randomized, double-blind study examined the effects of rehydration per se and rehydration plus carbohydrate (CHO) ingestion during recovery (REC) on subsequent endurance running capacity. Nine men ran at 70% VáO2max on a level treadmill for 90 min (T1) on two occasions, followed by a 4 hour REC and a further exhaustive run at the same speed (T2). During the first 3 hours of REC, subjects drank either a 6.9% CHO-electrolyte solution (CE) or a CHO- and electrolyte-free sweetened placebo (PL) every 30 min. Volumes prescribed were 200% of the fluid lost after T1, but the actual volume of fluid ingested during the REC ranged from 113-200% and 88. 5-200% of the body mass lost for the CE and PL trials (NS). However, positive fluid balance was found in both trials after REC. During T2, run time was 24.3 +/- 4.4 min longer in the CE trial (69.3 +/- 5.5 vs. 45.0 +/- 4.2 min; p <.05). Higher blood glucose concentrations were observed throughout REC in the CE trial. These results suggest that ingesting a CHO-electrolyte solution is more effective in restoring endurance capacity compared to the same large volume of placebo, even though complete rehydration was achieved in both trials.
Wong
S H
SH
Department of Sports Science and Physical Education, Chinese University of Hong Kong, Shatin, N.T. Hong Kong.
Williams
C
C
Adams
N
N
D000328:Adult; D001628:Beverages; D001786:Blood Glucose / Q000378:metabolism; D001810:Blood Volume; D001835:Body Weight; D002241:Carbohydrates / Q000008:administration & dosage*; D018592:Cross-Over Studies; D003681:Dehydration / Q000503:physiopathology / Q000628:therapy*; D004311:Double-Blind Method; D004573:Electrolytes / Q000008:administration & dosage* / Q000097:blood; D004734:Energy Metabolism / Q000502:physiology; D005080:Exercise Test; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005440:Fluid Therapy; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D010807:Physical Endurance / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D012420:Running / Q000502:physiology; D012881:Skin Temperature; D013997:Time Factors
D001786:Blood Glucose; D002241:Carbohydrates; D004573:Electrolytes; D005230:Fatty Acids, Nonesterified; D007328:Insulin