As an MMA fighter (and renowned peanut butter expert), Chuck Liddell is used to working up a sweat while wearing little in the way of clothing. Now the former light heavyweight champion has taken this comfort to its full-monty conclusion in a new viral video for Reebok.

In it, Liddell performs pulls up and squats while wearing nothing but a pair of sneakers. All the while, his equally naked girlfriend, Heidi Northcott (who was recently dating Jose Canseco), bounces up and down on an elliptical machine. Read on for the safe-for-work video.