Document Detail


Fat oxidation rate and the exercise intensity that elicits maximal fat oxidation decreases with pubertal status in young male subjects.
MedLine Citation:
PMID:  18535137     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The range of exercise intensities that elicit high fat oxidation rates (FOR) in youth and the influence of pubertal status on peak FOR are unknown. In a longitudinal design, we compared FOR over a range of exercise intensities in a small cohort of developing prepubertal male subjects. Five boys all at Tanner stage 1 (ages 11-12 yr) and nine men (ages 20-26 yr) underwent an incremental cycle ergometry test to volitional exhaustion. FOR curves were determined from indirect calorimetry during the final 30 s of each increment. The same protocol was duplicated annually in the boys as they progressed through puberty. The peak FOR was considerably higher (P<0.05) in boys at Tanner 1 (8.6+/-1.5 mg.kg lean body mass(-1).min(-1)) (mean+/-SD) compared with men (4.2+/-1.1 mg.kg lean body mass(-1).min(-1)). FOR dropped as boys developed through puberty (Tanner 2/3 peak rate=7.6+/-0.6 mg.kg lean body mass(-1).min(-1); Tanner 4 peak rate=5.4+/-1.8 mg.kg lean body mass(-1).min(-1), main effect of Tanner stage; P<0.05) to the levels found in men (not significant). The exercise intensity that elicited peak FOR was higher in the boys at Tanner 1 [56+/-6% peak aerobic power (VO2 peak)] than in men (31+/-4% VO2 peak) (P<0.001). This value tended to decrease by Tanner stage 4 (45+/-10% VO2 peak, main effect of Tanner stage; P=0.06). We conclude that, compared with men, prepubertal boys have higher relative FOR throughout a wide range of exercise intensities and that FOR drops as boys develop through puberty.
Authors:
M C Riddell; V K Jamnik; K E Iscoe; Brian W Timmons; N Gledhill
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2008-06-05
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  105     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2008 Aug 
Date Detail:
Created Date:  2008-08-05     Completed Date:  2008-10-10     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  742-8     Citation Subset:  IM    
Affiliation:
School of Kinesiology and Health Science, Faculty of Health, York University, 4700 Keele St., Toronto, ON, Canada M3J 1P3. mriddell@yorku.ca
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MeSH Terms
Descriptor/Qualifier:
Adolescent
Adult
Aging / physiology
Anaerobic Threshold / physiology
Body Composition / physiology
Calorimetry, Indirect
Carbohydrate Metabolism / physiology
Carbon Dioxide / metabolism
Child
Cohort Studies
Exercise / physiology*
Humans
Kinetics
Lipid Metabolism / physiology*
Longitudinal Studies
Male
Oxidation-Reduction
Puberty / physiology*
Chemical
Reg. No./Substance:
124-38-9/Carbon Dioxide

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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