Research conduced to date suggests that, unlike in the case of males, female runners can put their fertility at risk in case of intense running. According to the American College of Sports Medicine, 44 percent of athletic women experience menstrual irregularities or have experienced amenorrea at some time. In any case, as long as it is practiced moderately, running is beneficial for your overall health.
In the case of males, those who run on a regular basis and stay at a healthy weight are more likely to maintain a good sperm count in comparison with obese men. However, they should take care of the clothes they use, as continuously heating the testicles or using very tight-fitting shorts, can affect male fertility.