Pre-exercise glycerol hydration improves cycling endurance time

Montner, P., Stark, D.M., Riedesel, M.L., Murata, G., Robergs, R.A., Timms, M., & Chick, T.W. (1996) Pre-exercise glycerol hydration improves cycling endurance time. International Journal of Sports Medicine, 17(1), pp. 27-33.

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The effects of glycerol ingestion (GEH) on hydration and subsequent cycle ergometer submaximal load exercise were examined in well conditioned subjects. We hypothesized that GEH would reduce physiologic strain and increase endurance. The purpose of Study I (n = 11) was to determine if pre-exercise GEH (1.2 gm/kg glycerol in 26 ml/kg solution) compared to pre-exercise placebo hydration (PH) (26 ml/kg of aspartame flavoured water) lowered heart rate (HR), lowered rectal temperature (T(c)), and prolonged endurance time (ET) during submaximal load cycle ergometry. The purpose of Study II (n = 7) was to determine if the same pre-exercise regimen followed by carbohydrate oral replacement solution (ORS) during exercise also lowered HR, T(c), and prolonged ET. Both studies were double-blind, randomized, crossover trials, performed at an ambient temperature of 23.5-24.5°C, and humidity of 25-27%. Mean HR was lower by 2.8 ± 0.4 beats/min (p = 0.05) after GEH in Study I and by 4.4 ± 1.1 beats/min (p = 0.01) in Study II. Endurance time was prolonged after GEH in Study I (93.8 ± 14 min vs. 77.4 ± 9 min, p = 0.049) and in Study II (123.4 ± 17 min vs. 99.0 ± 11 min, p = 0.03). Rectal temperature did not differ between hydration regimens in both Study I and Study II. Thus, pre-exercise glycerol-enhanced hyperhydration lowers HR and prolongs ET even when combined with ORS during exercise. The regimens tested in this study could potentially be adapted for endurance activities.

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ID Code: 96956
Item Type: Journal Article
Refereed: Yes
Keywords: carbohydrate; glycerol, adult; article; bicycle ergometry; clinical trial; controlled clinical trial; controlled study; crossover procedure; double blind procedure; endurance; environmental temperature; heart rate; human; human experiment; humidity; hydration; ingestion; normal, NASA Discipline Cardiopulmonary; Non-NASA Center, Adult; Bicycling; Body Temperature; Cross-Over Studies; Double-Blind Method; Exercise; Female; Glycerol; Heart Rate; Humans; Male; Physical Endurance; Rehydration Solutions
DOI: 10.1055/s-2007-972804
ISSN: 0172-4622
Divisions: Current > QUT Faculties and Divisions > Faculty of Health
Current > Schools > School of Exercise & Nutrition Sciences
Copyright Owner: Copyright 1996 Georg Thieme Verlag Stuttgart · New York
Deposited On: 19 Jul 2016 00:48
Last Modified: 09 Aug 2016 00:52

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