Journal of Applied Physiology http://www.adinstruments.com/labchart/faseb
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Appl Physiol 92: 1562-1572, 2002. First published December 21, 2001; doi:10.1152/japplphysiol.00482.2001
8750-7587/02 $5.00
This Article
Right arrow Full Text Free
Right arrow Full Text (PDF) Free
Right arrow All Versions of this Article:
92/4/1562    most recent
00482.2001v1
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (24)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Jentjens, R. L. P. G.
Right arrow Articles by Jeukendrup, A. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Jentjens, R. L. P. G.
Right arrow Articles by Jeukendrup, A. E.
Vol. 92, Issue 4, 1562-1572, April 2002

Heat stress increases muscle glycogen use but reduces the oxidation of ingested carbohydrates during exercise

Roy L. P. G. Jentjens1, Anton J. M. Wagenmakers2, and Asker E. Jeukendrup1

1 Human Performance Laboratory, School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom; and 2 Department of Human Biology, Maastricht University, 6200 MD Maastricht, The Netherlands

The aim of the present study was to test the hypothesis that the oxidation rate of ingested carbohydrate (CHO) is impaired during exercise in the heat compared with a cool environment. Nine trained cyclists (maximal oxygen consumption 65 ± 1 ml · kg body wt-1 · min-1) exercised on two different occasions for 90 min at 55% maximum power ouptput at an ambient temperature of either 16.4 ± 0.2°C (cool trial) or 35.4 ± 0.1°C (heat trial). Subjects received 8% glucose solutions that were enriched with [U-13C]glucose for measurements of exogenous glucose, plasma glucose, liver-derived glucose and muscle glycogen oxidation. Exogenous glucose oxidation during the final 30 min of exercise was significantly (P < 0.05) lower in the heat compared with the cool trial (0.76 ± 0.06 vs. 0.84 ± 0.05 g/min). Muscle glycogen oxidation during the final 30 min of exercise was increased by 25% in the heat (2.07 ± 0.16 vs. 1.66 ± 0.09 g/min; P < 0.05), and liver-derived glucose oxidation was not different. There was a trend toward a higher total CHO oxidation and a lower plasma glucose oxidation in the heat although this did not reach statistical significance (P = 0.087 and P = 0.082, respectively). These results demonstrate that the oxidation rate of ingested CHO is reduced and muscle glycogen utilization is increased during exercise in the heat compared with a cool environment.

exogenous glucose; metabolism; stable isotopes; substrate utilization; cycling exercise


This article has been cited by other articles:


Home page
 J. Appl. Physiol.Home page
C. R. Abbiss, J. J. Peiffer, J. M. Peake, K. Nosaka, K. Suzuki, D. T. Martin, and P. B. Laursen
Effect of carbohydrate ingestion and ambient temperature on muscle fatigue development in endurance-trained male cyclists
J Appl Physiol, April 1, 2008; 104(4): 1021 - 1028.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
M. Robitaille, M.-C. Dube, S. J. Weisnagel, D. Prud'homme, D. Massicotte, F. Peronnet, and C. Lavoie
Substrate source utilization during moderate intensity exercise with glucose ingestion in Type 1 diabetic patients
J Appl Physiol, July 1, 2007; 103(1): 119 - 124.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
C. R. Harvey, R. Frew, D. Massicotte, F. Peronnet, and N. J. Rehrer
Muscle glycogen oxidation during prolonged exercise measured with oral [13C]glucose: comparison with changes in muscle glycogen content
J Appl Physiol, May 1, 2007; 102(5): 1773 - 1779.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
R. L. P. G. Jentjens, K. Underwood, J. Achten, K. Currell, C. H. Mann, and A. E. Jeukendrup
Exogenous carbohydrate oxidation rates are elevated after combined ingestion of glucose and fructose during exercise in the heat
J Appl Physiol, March 1, 2006; 100(3): 807 - 816.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
G. I Lancaster, Q. Khan, P. Drysdale, F. Wallace, A. E Jeukendrup, M. T Drayson, and M. Gleeson
The physiological regulation of toll-like receptor expression and function in humans
J. Physiol., March 15, 2005; 563(3): 945 - 955.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
G. I. Lancaster, Q. Khan, P. T. Drysdale, F. Wallace, A. E. Jeukendrup, M. T. Drayson, and M. Gleeson
Effect of prolonged exercise and carbohydrate ingestion on type 1 and type 2 T lymphocyte distribution and intracellular cytokine production in humans
J Appl Physiol, February 1, 2005; 98(2): 565 - 571.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
R. L. P. G. Jentjens, M. C. Venables, and A. E. Jeukendrup
Oxidation of exogenous glucose, sucrose, and maltose during prolonged cycling exercise
J Appl Physiol, April 1, 2004; 96(4): 1285 - 1291.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online