Running exercise of different duration and intensity:: effect on endothelial progenitor cells in healthy subjects

Background Increased numbers of circulating endothelial progenitor cells (EPC) are associated with improved vascular function. Exercise is a central component of the primary prevention of vascular diseases. The effect of physical activity on circulating EPC in healthy individuals is not known. Design A prospective crossover study. Methods and results In order to study a potential link between the extent of physical exercise and progenitor cells in humans, EPC were quantified by flow cytometry and cell culture in 25 healthy volunteers undergoing three protocols of running exercise. Intensive running, defined as 30 min at 100% of the velocity of the individual anaerobic threshold (IAT; similar to 82% maximal oxygen consumption; VO(2)max), as well as moderate running with 30 min at 80% of the velocity of the IAT (similar to 68% VO(2)max), increased circulating EPC numbers to 235 +/- 93% and 263 +/- 106% of control levels, respectively. However, moderate short-term running for 10 min did not upregulate EPC counts. The maximum increase in circulating EPC numbers was observed 10-30 min after intensive running. Exercise increased EPC migratory and colony-forming capacity. Conclusions Intensive and moderate exercising for 30 min, but not for 10 min, increased circulating levels of EPC, which may represent an important beneficial outcome of physical exercise. The data support the notion that increased numbers of EPC correlate with cardiovascular health and suggest EPC quantification as a novel surrogate parameter of the vascular effects of exercising.