Increased lipid oxidation during exercise in obese pubertal girls: A QUALITY study


  • Funding agencies: The QUALITY Cohort is funded by the Canadian Institutes of Health Research, the Heart and Stroke Foundation of Canada and the Fonds de la recherche en santé du Québec. Jennifer O'Loughlin holds a Canada Research Chair in the Early Determinants of Adult Chronic Disease. Angelo Tremblay holds Canada Research Chair in Environment and Energy Balance.



This study explores differences in LO rates between pre-pubertal and pubertal girls of three body weight status groups.


The sample included 39 pre-pubertal girls [12 normal-weight (NW), 12 overweight (OW), and 15 obese (OB)] and 37 pubertal girls [16 NW, 10 OW, and 11 OB]. Following a rest period, the girls performed a graded maximal cycling test. The %LO contribution was computed at each stage.


The %LO contribution did not differ between NW, OW, or OB pre-pubertal girls at each exercise stage. In contrast, pubertal OB girls showed a statistically significantly higher %LO contribution at 25, 50, and 75 W stages compared with OW and NW as well as with OB pre-pubertal girls.


Our results demonstrate that entering puberty is a period associated with differentiation in substrate selection in obese girls. A higher %LO contribution may help girls to solicit more fat while performing submaximal exercise.