Menopausal Transition Does Not Influence Skeletal Muscle Capillary Growth In Response To Cycle Training In Women

The influence of the menopausal transition, with a consequent loss of estrogen, on capillary growth in response to exercise training remains unknown. In the present study, we evaluated the effect of a period of intense endurance training on skeletal muscle angiogenesis in late premenopausal and recent postmenopausal women with an age difference of <4 yr. Skeletal muscle biopsies were obtained from the thigh muscle before and after 12 wk of intense aerobic cycle training and analyzed for capillarization, fiber-type distribution, and content of vascular endothelial growth factor (VEGF). At baseline, there was no difference in capillary per fiber ratio (C:F; 1.41 +/- 0.22 vs. 1.40 +/- 0.30), capillary density (CD; 305 +/- 61 vs. 336 +/- 52 mm 2 ), muscle fiber area (MFA; 4,889 +/- 1,868 vs. 4,195 +/- 749), or distribution of muscle fiber type I (47.3% +/- 10.1% vs. 49.3% +/- 15.1%), between the preand postmenopausal women, respectively. There was a main effect of training on the C:F ratio (+ 9.2% and -12.1%, for the preand postmenopausal women, respectively) and the CD (+ 6.9% and + 8.9%, for the pre- and postmenopausal women, respectively). MFA and fiber-type distribution were unaltered by training. Skeletal muscle VEGF protein content was similar between groups at baseline, and there was a main effect of training (+21.1% and + 27.2%, for the pre- and postmenopausal women, respectively). In conclusion, the loss of estrogen per se at menopause does not influence the capillary growth response to intense aerobic exercise training.NEW & NOTEWORTHY We evaluated the effect of 12 wk of intense aerobic exercise training on skeletal muscle angiogenesis in late pre- and recent postmenopausal women, with <4yr of age difference. There was a main effect of training on capillary per fiber ratio, capillary density, and muscle VEGF protein content, with no difference between groups. It is concluded that the loss of estrogen per se at menopause does not influence the capillary growth response to intense aerobic training.