The effect of a 20-week endurance training program on adipose-tissue morphology and lipolysis in men and women.

In order to assess the effect of endurance training on adipose-tissue morphology and lipolysis, 22 adult subjects (11 men and 11 women) took part in a 20-week ergocycle training program, four to five days a week, 40 minutes a day, at 80% of their maximal heart rate. Before and after training, they were submitted to an adipose-tissue biopsy in the suprailiac region. Fat cell weight (FCW), and lipolytic activity were determined on isolated fat cells. For the whole sample, training significantly reduced FCW (pre: 0.40 +/- 0.13 (mean +/- SD) versus post: 0.36 +/- 0.13 micrograms; P less than 0.05), percentage of fat (pre: 22.0 +/- 8.3 versus post: 19.7 +/- 8.1%; P less than 0.05), and increased adipocyte epinephrine maximal stimulated lipolysis (ESL) (pre: 1.08 +/- 0.49 versus post: 1.69 +/- 0.67 mumol glycerol/30 min/10(6) cells; P less than 0.001). No changes were observed in fat cell number. In women, however, training induced no changes in the fatness indicators (% fat, sum of skinfolds, FCW). The exercise program significantly lowered the adiposity of men (% fat: P less than 0.001; sum of skinfolds: P less than 0.01; FCW: P less than 0.05). In both sexes, a significant increase in ESL was observed after training. ESL of men, however, responded better than that of women to training (ESL of women: 1.36 +/- 0.67 versus ESL of men: 2.02 +/- 0.50 mumol glycerol/30 min/10(6) cells; P less than 0.05), with increases over pre-training values of 46% and 66% in women and men, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)