Effect of high and low rates of fluid intake on post-exercise rehydration

Int J Sport Nutr Exerc Metab. 2002 Mar;12(1):14-23. doi: 10.1123/ijsnem.12.1.14.

Abstract

The effect of a high (H) and a low (L) rate of post-exercise fluid consumption on plasma volume and fluid balance restoration was investigated. Eight well-trained cyclists were dehydrated at 3% of body weight (BW) by cycling at 28 degrees C. During the recovery period, they ingested a carbohydrate-electrolyte solution in a volume equivalent to 120% of BW loss. Randomly, they ingested 60%, 40%, and 20% in the 1st, 2nd, and 3rd hours of the recovery period, respectively (H), or 24% x h(-1) during 5 hours (L). BW loss was similar for both trials and resulted in a total drink intake of 2.6 +/- 0.1 kg. Urine output in H exceeded significantly that of L in the 2nd and 3rd hours. This was reversed in the 5th and 6th hours. Plasma volume and fluid balance increased more rapidly in H compared to L. After 6 hours this difference disappeared. It is concluded that H results in a faster rate of plasma volume and fluid balance restoration compared to L, despite a temporary large urine output.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Beverages
  • Bicycling
  • Body Weight / physiology
  • Cross-Over Studies
  • Dehydration / blood
  • Dehydration / therapy*
  • Dehydration / urine
  • Dietary Carbohydrates / administration & dosage
  • Drinking
  • Electrolytes / administration & dosage
  • Exercise / physiology*
  • Exercise Test
  • Fluid Therapy / methods*
  • Humans
  • Kinetics
  • Male
  • Osmolar Concentration
  • Plasma Volume
  • Sodium / analysis
  • Sodium / metabolism
  • Urination / physiology*
  • Water-Electrolyte Balance

Substances

  • Dietary Carbohydrates
  • Electrolytes
  • Sodium