Fat oxidation rate and the exercise intensity that elicits maximal fat oxidation decreases with pubertal status in young male subjects
| Autor: | Katherine E. Iscoe, Michael C. Riddell, Veronica K. Jamnik, Brian W. Timmons, Norman Gledhill |
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| Rok vydání: | 2008 |
| Předmět: |
Adult
Male Aging medicine.medical_specialty Adolescent Anaerobic Threshold Physiology Physical exercise Cohort Studies Fat oxidation Physiology (medical) Internal medicine medicine High fat Humans Longitudinal Studies Exercise physiology Child Exercise Young male Diminution business.industry Puberty Calorimetry Indirect Carbon Dioxide Lipid Metabolism Kinetics Endocrinology Fat oxidation rate Body Composition Exercise intensity Carbohydrate Metabolism business Oxidation-Reduction |
| Zdroj: | Journal of Applied Physiology. 105:742-748 |
| ISSN: | 1522-1601 8750-7587 |
| DOI: | 10.1152/japplphysiol.01256.2007 |
| Popis: | 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 (V̇o2 peak)] than in men (31 ± 4% V̇o2 peak) ( P < 0.001). This value tended to decrease by Tanner stage 4 (45 ± 10% V̇o2 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. |
| Databáze: | OpenAIRE |
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