Ben stiller picks up a hitchhiker (who turns out to be a murderer ) and the hitch says he has invented the 2 minute workout. They stop to do a pee in the scrub when a police bust happens and the bushes are full of guys together.!

The movie is called something about Mary and it was a 2 min work out it was something called 7 minute abs a knock off 8 minute abs lol

Thanks for that . As soon as I started reading your answer I remembered. Funny how one's mind just draws a blank.