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CHANGES OF RESPIRATORY EXCHANGE RATIO IN CHILDREN AND ADOLESCENTS: A LONGITUDINAL STUDY
Željko Jeleč
; General Hospital "Dr. Ivo Pedišić", Sisak, Croatia
Branka R Matković
; Faculty of Kinesiology, University of Zagreb, Zagreb, Croatia
Ana Lebo
; PLIVA Croatia Ltd, Croatia
Dražen Jeleč
; Roche d.o.o., Zagreb, Croatia
Andro Matković
; Health Center Zagreb - Cener, Croatia
Sažetak
We conducted a longitudinal study to examine changes in the respiratory exchange ratio (RER) during progressively increasing body exertion in children and adolescents of female sex. In this analysis we only included 23 examinees for whom we had all yearly measurements from examinee's age 9 years until 18 years of age.
The data were analyzed according to the chronological and biological age. According to both criteria, the highest RER values were recorded at moments of maximum exertion and they did not increase with age. We found the highest RER values were in the year of the menarche.
We interpret these results as related to the effect of estrogen. The beginning of sexual development involves a gradual increase in estrogen plasma concentrations. At one point serum levels of estrogen reach a level high enough to allow for maximum RER values, i.e. causing the optimium anaerobic capacity of the examinee. this threshold estrogen value varies between individuals.
Ključne riječi
children; respiratory exchange ratio; substrate utilization
Hrčak ID:
166259
URI
Datum izdavanja:
20.11.2015.
Posjeta: 1.937 *