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 language | English (US) |
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Pages (from-to) | 1039-1045 |
Number of pages | 7 |
Journal | Medicine and science in sports and exercise |
Volume | 33 |
Issue number | 6 |
DOIs | |
State | Published - 2001 |
Externally published | Yes |
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