Int J Sports Med 2006; 27(5): 407-414
DOI: 10.1055/s-2005-865751
Training & Testing

© Georg Thieme Verlag KG Stuttgart · New York

Comparison of the Type of Substrate Oxidation During Exercise Between Pre and Post Pubertal Markedly Obese Boys

F. Brandou1 , A. M. Savy-Pacaux2 , J. Marie2 , J. F. Brun1 , J. Mercier1
  • 1Service Central de Physiologie Clinique, Unité CERAMM (Centre d'Exploration et de Réadaptation des Anomalies Métaboliques et Musculaires), CHU Lapeyronie, Montpellier Cedex 5, France and Département de Physiologie des Interactions, EA 701 «Muscles et pathologies chroniques», Faculté de Médecine, Montpellier Cedex 2, France
  • 2Perle Cerdane, Maison d'enfants à caractère sanitaire spécialisé, Osseja Cedex, France
Further Information

Publication History

Accepted after revision: April 15, 2005

Publication Date:
01 February 2006 (online)

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Abstract

The aim of this study was to investigate, in markedly obese children, the effect of puberty on substrate oxidation during an acute bout of exercise. Two groups of markedly obese boys (7 pre pubertal, 8 post pubertal, matched for adiposity) performed an exercise-test designed for measuring carbohydrate and fat oxidation with indirect calorimetry, and consisting of five six-minute steady-state workloads at 20, 30, 40, 50, and 60 % of the theoretical maximal aerobic power. Fat oxidation (mg · min-1) is correlated to fat free mass (FFM) (r = 0.7, p = 0.02). When expressed in crude flow rate units, fat oxidation is slightly higher in PostP than PreP children (p < 0.05). However, when expressed per unit of FFM or as a percentage of total fuel oxidation, fat oxidation is lower in PostP than PreP children (p < 0.05). Multivariable analysis shows that the influence of age on the ability to oxidize fat at exercise is explained by the pubertal increase in FFM. In markedly obese children during puberty, the ability of each kg of FFM to oxidize fat at exercise decreases (- 28 % at 20 %Wmax th), but the pubertal increase in FFM overcomes this effect, resulting in an increase in whole body ability to oxidize fat at exercise (+ 17,3 % at 20 %Wmax th).

References

F. Brandou

Département de Physiologie des Interactions, EA 701 «Muscles et pathologies chroniques», Faculté de Médecine

Bd Henri IV

34060 Montpellier Cedex 2

France

Phone: + 33467600766

Fax: + 33 4 67 60 69 04

Email: fredbrandou@yahoo.fr