TV viewing linked to lower sperm count
5th February 2013 - Healthy young men who watch TV for more than 20 hours a week have almost half the sperm count of men who watch very little television. Conversely, according to the findings of a study published in the British Journal of Sports Medicine, men who do 15 or more hours of moderate to vigorous exercise every week have sperm counts that are 73% higher than those who exercise for less than five hours a week.
Dr Allan Pacey, British Fertility Society chairman and senior lecturer in andrology at the University of Sheffield told BootsWebMD: "This was a small, well controlled study and the conclusions are plausible."
He says the findings fit with what fertility experts already know: "We know that men who wear too tight underwear have poorer sperm. So it’s not a million miles away from sitting on the sofa on your bum for too long and heating up your testicles for too long. It’s the same mechanism I would suspect."
And the findings about helping sperm quality with exercise also fit: "Men who are out on the golf course are not only getting cardiovascular benefits from doing even light exercise, but there are also some metabolic benefits as well.
"The slight benefits of doing exercise and the detriment of sitting on your ‘crown jewels’ follows the pattern that you would predict really."
Semen quality appears to have deteriorated in most Western countries over the past few decades. According to the authors of the study the reason is unclear. They set out to find if an increasingly sedentary lifestyle might be a contributory factor.
They analysed the semen quality of 189 American men between the ages of 18 to 22 in 2009-10, all of whom were from New York State.
The men were asked about the quantity and intensity of weekly exercise over the preceding three months and how much time they spent watching television, DVDs, or videos over the same period.
They were also asked about factors that might affect sperm quality, including medical or reproductive health problems, diet, stress levels and smoking.
Impact of exercise
The men were asked to say how many hours they usually spend a week doing vigorous, moderate or mild exercise. They also said how much TV they watched on an average day, from none/almost none at all to over 10 hours.
Men who were more physically active tended to have a healthier diet than those who watched a lot of TV every week.
The analysis showed that those who were the most physically active-15 or more hours a week-had a 73% higher sperm count than the least physically active.
When analysed by exercise intensity, the results showed that light physical exercise made no difference to the sperm count, no matter how frequent it was.