That dip may make it more difficult to father a child, says study coauthor Dr Lærke Priskorn, of the University of Copenhagen.
Interestingly, men who played on the computer for the same amount of time - another activity where you remain parked on your butt - didn’t experience a drop in those semen parameters.
Researchers aren’t sure yet what it is about TV specifically that’s so harmful to your sperm.
It’s a more passive activity than using a computer, Priskorn says, and you might take more active breaks from a computer than you would from TV.
It’s possible that all the stillness increases the temperature in your scrotum, which can mess with sperm production, she says.
The lack of exercise could also be to blame: antioxidant enzymes sparked by physical activity can help protect your developing sperm cells against damage.
Or it could just be that guys who watch a ton of TV are also more likely to be overweight or drink excessively, both of which hurt your sperm, Priskorn notes.
Your move: If you’re trying to become a dad, it doesn’t hurt to cut down on couch time. And when you do sit down to catch up on Narcos, take breaks between episodes to do something active - like this Lower Body Workout You Can Do Anytime, Anywhere.
This article originally appeared on MensHealth.com