Couch potatoes may have lower sperm counts than men who exercise regularly
Many scientists believe that sperm counts in developed countries have declined over the last decades. Smoking, obesity, Western diet, environmental pollution and other lifestyle factors have been possible suspects. Now we can add TV viewing to the list.
Harvard researchers asked young men in Rochester, NY, how much they watched TV and DVDs, as well as how much time they spent exercising vigorously. The 189 participants also provided sperm specimens. The results were recently published in the British Journal of Sports Medicine.
Men watching the most television (20 hours per week) had sperm counts that were 44 percent lower than men watching the least amount of TV. For exercise, it was the opposite. The most active guys’ sperm counts were 77 percent higher than the least active. (The more active men also tended to have higher quality diets, which could have helped boost the count.)
Why this is so is still unclear. One possibility is that TV watching means increased pressure and temperature in the scrotum, known to be a cause of diminished semen quality. Another possible reason could be oxidative chemicals, which are toxic to sperm. Exercise decreases such oxidative stress while poor eating habits increase oxidative stress.
Whether these men’s lower sperm counts translate into reduced fertility is not known, since they were not actively trying to achieve pregnancy. But it seems prudent to get up off the couch, you gentlemen wishing to become dads!