Sitting for long periods of time can affect fertility in men. The testicles can become overheated, hindering sperm production. When sperm reach temperatures over 93 degrees, they can't be produced or stored properly. Temperatures over 102 (a hundred and two) can actually kill them. It takes 70 to 80 days for sperm cells to reach maturity, so if you destroy some, they won't be replaced for over two months. If your job requires you to remain seated for extended periods of time, try taking a break and walking around occasionally. This will help cool them off.