Journal of Applied Physiology, Vol 58, Issue 1 230-235, Copyright © 1985 by American Physiological Society
Endurance training and glucose conversion into triglycerides in human fat cells
R. Savard, J. P. Despres, M. Marcotte and C. Bouchard
To study the influence of endurance training on glucose conversion into fat
cell triglycerides, 24 (13 women, 11 men) inactive subjects (25.0 +/- 3.8
yr of age) took part in a 20-wk ergocycle training program 4 days and
increasing to 5 days/wk, 40-45 min/day, starting at 60% and increasing to
85% of the heart rate reserve. Several body fatness indicators were
measured before and after the training program: seven skinfold thicknesses,
percent fat, and mean fat cell weight. Fat cell basal and maximal
insulin-stimulated glucose conversion into triglycerides were also
determined using [14C]glucose. Body fatness indicators decreased
significantly after training only in male subjects (P less than 0.05).
Basal and maximal insulin-stimulated glucose conversion into triglycerides
increased significantly with training (P less than 0.05): pretest values
(nanomoles glucose per hour per 10(6) cells) being 24.9 +/- 2.1 and 28.7
+/- 2.5, while post-test values were 30.1 +/- 3.2 and 33.0 +/- 3.4 for
basal and insulin-stimulated values, respectively. However, this lipogenic
increase was only observed in male subjects (P less than 0.01). Changes in
body fatness indicators induced by training were negatively correlated with
changes induced in fat cell glucose conversion into triglycerides (-0.24
less than or equal to r less than or equal to -0.45). These results
demonstrate that endurance training increases fat cell glucose conversion
into triglycerides and suggest that adipose tissue metabolism is part of
the adaptive response to training. Moreover, it appears that adipose tissue
response to aerobic training is more efficient in males than in females.
