Did you know guys have two different types of sweat? We didn't either.
But we soon learned that while gym shorts aren't stink-free, the real culprit is stress sweat. The sweat you get when your adrenaline kicks into overdrive and your pores seep nutrients. The nutrients attract bacteria. The bacteria eat the nutrients, and then, for all intents and purposes, fart them out. And that, my friend, is why you stink.
It's possible I left out a few pertinent details. Hopefully these spots we made help fill in the gaps.