If you're overweight, there's a good chance that your sperm are in trouble. (I'm assuming you're male if you're reading this on a website with the tagline "What Men Need to Know," but if not, welcome.) People over at the journal Fertility and Sterility did some fancy science and cracked this tough nut. This is what you need to know, be you male or female:

1. Obese men tend to have fewer sperm. Period.

2. These smaller herds tend to have fewer "ultra-speedy" sperms.

3. These herds also have fewer "beeline" sperms that travel in a straight line.

4. Leaner men have more Michael Phelpses.

Read more about it, and all the dull statistical nuances, in the Montreal Gazette