Effects of a two-month rehabilitation program on substrate utilization during exercise in obese adolescents.

BACKGROUND We assessed the impact of an exercise and diet program for two weeks in a specialized institute and six weeks at home on body composition and exercise metabolism in obese adolescents. METHODS Fourteen obese adolescents took part in the two-week training course and seven continued exercise and diet at home. The substrate crossover point and the maximal fat oxidation point (Lipox max) were determined before and after the program, using indirect calorimetry. Individualized exercise training at Lipox max was programmed over the two months. RESULTS At the end of the two-week program, all adolescents showed a decrease in weight (p<0.001). Only the seven subjects who continued exercise training at home showed improved exercise fat use (increased crossover point of 17% +/- 3 (p<0.005) and Lipox max of 12.5% +/- 1.5 (p<0.005)). CONCLUSION The teenagers who had performed this targeted regular training for two months exhibit an increase in their ability to oxidize lipids at exercise. This increase is no longer found in those treated by diet alone. The efficiency of this targeted training protocol based on calorimetry for the treatment of teenager obesity will require longer studies on greater samples of subjects.