Of course you want to pass on your amazingly, super seed that contains your intelligence, good looks, humor and chiseled physique. In order to let your boys swim and avoid their certain death, researchers have found that specific environmental factors exist that will deplete your arsenal of sperm. Evidently there is a correlation between watching more TV and having a decreased amount of sperm, but that's not one of these five. 

1. Industrial chemicals, such as benzenes, herbicides, pesticides, and certain painting material
2. Heavy metals, especially lead
3. Radiation or X-rays to the pelvic area
4. Overheating, such as frequent use of saunas, hot tubs, and yes – computers in your lap.  They overheat your testicles and decrease sperm production
5. Prolonged bicycling.  For all those guys who like to bike, watch out because this could be doing some damage to your sperm

It looks like our days of bicycle races and genital radiation are over. As for hot tubbing, we'll let you know when we give that up.