Perceptual responses in the heat after brief intravenous versus oral rehydration

C. M. Maresh, J. A. Herrera-Soto, L. E. Armstrong, D. J. Casa, S. A. Kavouras, Jr Hacker, T. A. Elliott, J. Stoppani, T. P. Scheett

Research output: Contribution to journalArticle

41 Scopus citations

Abstract

Purpose: The purpose of the study was to compare the effects of a brief period (20 min) of intravenous (IV) fluid rehydration and oral (ORAL) rehydration on ratings of perceived exertion (RPE), thirst, and thermal sensation (TS) during exercise in the heat. Methods: After dehydration (-4% of body weight), eight nonacclimated highly trained cyclists (age = 24 ± 1 yr; V̇O2 = 61.4 ± 0.8 mL·kg·min-1) performed three experimental trials. Rehydration (randomized, cross-over design) included: 1) ORAL (0.45% NaCl) equal to 50% of prior dehydration; 2) IV (0.45% NaCl) equal to 50% of prior dehydration; and 3) a control (CON), no fluid trial. Subjects then cycled at 74% V̇O2peak until volitional exhaustion in a hot environment (37°C). Results: Central (C-), local (L-), and overall-RPE (O-RPE) were significantly higher in CON compared to ORAL and IV at minutes 5 and 15 of exercise. C-RPE responses at minute 5 of exercise were lower (P < 0.05) during ORAL compared with IV, and C-RPE and O-RPE responses at minute 15 were lower (P < 0.05) during ORAL compared with IV. TS responses during CON were higher (P < 0.05) than ORAL and IV at minute 5, and TS was higher (P < 0.05) during IV versus ORAL at minute 15. TS were significantly correlated with all RPE responses at minute 15 in all trials. Thirst ratings were lower (P < 0.05) during ORAL compared with CON and IV at minutes 0, 5, and 15. Conclusion: It was concluded that ORAL resulted in lower RPE, thirst, and TS compared with CON and IV during exercise in the heat.

Original languageEnglish (US)
Pages (from-to)1039-1045
Number of pages7
JournalMedicine and science in sports and exercise
Volume33
Issue number6
DOIs
StatePublished - Jan 1 2001
Externally publishedYes

Keywords

  • Dehydration
  • Exhaustive exercise
  • Ratings of perceived exertion
  • Thermal sensations
  • Thirst

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation

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  • Cite this

    Maresh, C. M., Herrera-Soto, J. A., Armstrong, L. E., Casa, D. J., Kavouras, S. A., Hacker, J., Elliott, T. A., Stoppani, J., & Scheett, T. P. (2001). Perceptual responses in the heat after brief intravenous versus oral rehydration. Medicine and science in sports and exercise, 33(6), 1039-1045. https://doi.org/10.1097/00005768-200106000-00025