Dude (I don't say "Dude" often, but it feels appropriate here), it's just you and me on these treadmills...and I know that I myself didn't fart, so it must be you! Don't pretend you didn't do it. There's no one else in sight, you are sooooo busted!
And on while we're venting about gym pet peeves, please don't do any of the following either: have loud conversations on your cellphone (get an office!), wear extremely strong perfume or cologne that makes it hard for me to breathe (as if exercise didn't make it hard enough), make loud grunting noises (where am I, Gold's Gym?).
THANK YOU! Follow all these simple instructions and we will get along just fine. And I promise not to beat you up (have you seen my guns? I have been working out a lot lately! Who do you think is smelling all your farts?)