Time-course effects of endurance training on fat oxidation in sedentary elderly people

OBJECTIVE: To investigate alterations in whole body fat oxidation after 7 a nd 14 weeks of progressive endurance training in sedentary elderly subjects . DESIGN: Longitudinal, 14 weeks of progressive endurance training on a cycle ergometer (3 training sessions per week). Full sets of measurements were p erformed before, and after 7 and 14 weeks of training. SUBJECTS: 13 healthy sedentary subjects (5 men, 8 women) (age 62.8+/-2.3 y) , MEASUREMENTS: 24h indirect calorimetric measurements under standardised con ditions: light-activity programme, fixed food composition, neutral daily en ergy balance. Body composition (by isotope dilution and skinfold thicknesse s). Maximal oxygen consumption. RESULTS: Loss of 0.7 kg fat mass in the first 7 weeks of training and a fur ther 2.4 kg of fat in the second 7 weeks. There was a transient increase in sleeping fat oxidation after 7 weeks of training (+26.1%), associated with transient increase in daily fat oxidation (+/-11.9%), but fat oxidation th en returned to baseline values in the second 7 weeks. There was a correlati on between within-subject changes in sleeping fat oxidation after 7 weeks o f training and variations in FFM (r=0.62 P=0.02) and maximal oxygen consump tion (r=-0.56, P < 0.05). CONCLUSION: In sedentary elderly subjects, progressive endurance training w as associated with a transient increase in sleeping fat oxidation and daily fat oxidation. In free-living conditions, possible changes in daily fat ox idation may have induced a negative fat balance, as judged by fat mass loss .