To enhance microvasculature development is a major adaptation phenomenon after aerobic exercise training. Traditionally, morphometric observation was used to calculate the number of vessels. In the process of angiogenesis, the most important angiogenic factor is VEGF (vascular endothelial growth factor). The VEGF expression can be increased after acute exercise and exercise training. Acute exercises or exercise training not only activate VEGF but also form new microvessels. VEGF expression may act as an index of microvascular regenesis in sports science.