[Effect of intensive, strength-building exercise training on the fine structure of human skeletal muscle capillaries]

The effects of a five-weeks training programme and of long-term strenuous exercise on capillary endothelial cells (E), basement membranes (B), and pericytes (P) of m. vastus lateralis were studied morphometrically in 2 groups of healthy young men. The five-weeks training programme was performed by 7 sports students, whereas the long-term effect of strength type exercise was investigated on 6 top level athletes. As a result of the five-weeks training period we found a swelling of the E (23%, p less than 0.05), an increase in number and cross-sectional areas of P (33%, p less than 0.05) as well as signs of endomysial connective tissue stimulation. With the exception of connective tissue reaction this post-training data corresponds to the structural features of the top level athletes. The mean B-thickness (132 +/- 32 nm) was almost the same in both groups and was not affected by the five-weeks training period.