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

Abstract

OBJECTIVE: To investigate alterations in whole body fat oxidation after 7 and 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 performed 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: 24 h indirect calorimetric measurements under standardised conditions: light-activity programme, fixed food composition, neutral daily energy balance. Body composition (by isotope dilution and skinfold thicknesses). Maximal oxygen consumption.

RESULTS: Loss of 0.7 kg fat mass in the first 7 weeks of training and a further 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 then returned to baseline values in the second 7 weeks. There was a correlation between within-subject changes in sleeping fat oxidation after 7 weeks of training and variations in FFM (r=0.62, P=0.02) and maximal oxygen consumption (r=−0.56, P<0.05).

CONCLUSION: In sedentary elderly subjects, progressive endurance training was associated with a transient increase in sleeping fat oxidation and daily fat oxidation. In free-living conditions, possible changes in daily fat oxidation may have induced a negative fat balance, as judged by fat mass loss.