Journal of Applied Physiology Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Appl Physiol 94: 278-284, 2003. First published September 13, 2002; doi:10.1152/japplphysiol.00140.2002
8750-7587/03 $5.00
This Article
Right arrow Full Text Free
Right arrow Full Text (PDF) Free
Right arrow All Versions of this Article:
94/1/278    most recent
00140.2002v1
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 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 Web of Science (27)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Timmons, B. W.
Right arrow Articles by Riddell, M. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Timmons, B. W.
Right arrow Articles by Riddell, M. C.
Vol. 94, Issue 1, 278-284, January 2003

Oxidation rate of exogenous carbohydrate during exercise is higher in boys than in men

Brian W. Timmons1, Oded Bar-Or1, and Michael C. Riddell2

1 Children's Exercise and Nutrition Centre, McMaster University, Hamilton L8N 3Z5; and 2 Department of Kinesiology and Health Science, Faculty of Pure and Applied Sciences, York University, Toronto, Ontario, Canada M3J 1P3

To determine whether the relative utilization of exogenous carbohydrate (CHOexo) differs between children and adults, substrate utilization during 60 min of cycling at 70% peak O2 uptake was studied in 12 pre- and early pubertal boys (9.8 ± 0.1 yr) and 10 men (22.1 ± 0.5 yr) on two occasions. Subjects consumed either a placebo or a 13C-enriched 6% CHOexo beverage (total volume per trial: 24 ml/kg). Substrate utilization was calculated for the final 30 min of exercise. During both trials, total fat oxidation was higher (5.4 ± 0.5 vs. 3.0 ± 0.4 mg · kg-1 · min-1, P < 0.001) and total CHO oxidation lower (27.4 ± 1.5 vs. 34.8 ± 1.2 mg · kg-1 · min-1, P < 0.001) in boys than in men, respectively. During the CHOexo trial, CHOexo oxidation was higher (P < 0.001) in boys (8.8 ± 0.5 mg · kg-1 · min-1) than in men (6.2 ± 0.5 mg · kg-1 · min-1) and provided a greater (P < 0.001) relative proportion of total energy in boys (21.8 ± 1.4%) than in men (14.6 ± 0.9%). These results suggest that, although endogenous CHO utilization during exercise is lower, the relative oxidation of ingested CHO is considerably higher in boys than in men. The greater reliance on CHOexo in boys may be important in preserving endogenous fuels and may be related to pubertal status.

children; adults; carbon-13 isotope; substrate utilization


This article has been cited by other articles:


Home page
 J. Appl. Physiol.Home page
M. C. Riddell
The endocrine response and substrate utilization during exercise in children and adolescents
J Appl Physiol, August 1, 2008; 105(2): 725 - 733.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
M. C. Riddell, V. K. Jamnik, K. E. Iscoe, B. W. Timmons, and N. Gledhill
Fat oxidation rate and the exercise intensity that elicits maximal fat oxidation decreases with pubertal status in young male subjects
J Appl Physiol, August 1, 2008; 105(2): 742 - 748.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
B. W. Timmons, O. Bar-Or, and M. C. Riddell
Energy substrate utilization during prolonged exercise with and without carbohydrate intake in preadolescent and adolescent girls
J Appl Physiol, September 1, 2007; 103(3): 995 - 1000.
[Abstract] [Full Text] [PDF]


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