Young men who watch TV for just three hours a day have half the sperm count of men rarely found in front of the box, warn researchers. For the first time, a study shows falling sperm quality is linked to lower levels of physical activity. Men who are mostly sedentary lose out to those who are moderately active, says the Harvard University study in the British Journal of Sports Medicine. Experts say the effect could be due to lack of exercise, or to overheating of the testicles caused by prolonged sitting. Men wanting to father a child are currently urged against wearing tight underpants to improve sperm quality, while drivers and cyclists may also be at risk. In the latest study from the Harvard School of Public Health (HSPH), healthy young men who watched more than 20 hours of TV each week had a 44 per cent lower sperm count than those who watched almost no TV. Men who exercised for 15 or more hours weekly at a moderate to vigorous rate had a 73 per cent higher sperm count than those who exercised less than five hours per week. Mild exercise did not affect sperm quality. Mail Online
