Attention, gentlemen of child-rearing age. Too much time in front of the television may be reducing your fertility.
A Harvard University study suggests a trend of lower-quality sperm concentration among men in Western countries could be linked to television watching habits.
The study supports other research that finds reduced physical activity can be harmful to sperm production.
Scientists asked 189 volunteers questions about how much they exercise -- and how often they watch T-V.
They then took semen samples from each of the men.
Volunteers who said they exercise 15 hours or more per week had much higher sperm concentration.
By contrast, those who watched more than 20 hours of TV had just half as many sperm cells as those who watch no TV.
The study's authors say more research is needed because of their small group sample size.