Researchers from Harvard University have linked TV viewing and lack of exercise to a low sperm count, according to a study published n the British Journal of Sports Medicine.
The study found that while watching TV for 20 hours or more a week can lower sperm count, adding 15 hours or more of exercise a week may increase it.
Researchers wanted to examine whether or not there may be a relationship between falling sperm counts — which have been recorded around the world over the past few decades — and lifestyle factors. The study was done by surveying 189 New York college students on the amount of time they spent watching TV and exercising, and then studying their sperm samples. They were also asked about their diets, stress levels, and whether or not they smoked. Those who exercised 15 hours or more a week had 73% higher sperm count than those who exercised less. Additionally, the 25% of men in the study who watched 20 hours or more a week of TV had a 44% lower sperm count than those who watched less.
Dr. Jorge Chavarro, assistant professor of nutrition and epidemiology at Harvard School of Public Health, and one of the study’s authors, said, “I was surprised to see the strength of the association…We expected an inverse relationship, but we didn’t know to what extent.”
It is unclear just why there is such a strong association, though it is posited that it may have to do with the higher obesity rates and scrotal temperatures involved in prolonged TV watching.
Dr Allan Pacey, senior lecturer in andrology at the University of Sheffield, commented: “It remains to be seen if coaxing a TV-watching couch potato into doing some regular exercise could actually improve his sperm count. Or whether there exists an unknown fundamental difference between men who like exercise and those who do not which might account for the findings.”