Wahlberg left the instructor to call the shots, but it was obvious Lassner was struggling to keep up - as early on as stretching.
Throughout the footage, Lassner can be heard screeching and complaining. "Just don't want to throw up at F45," he jokes. "45 minutes has never taken longer."
"I'm so dzzy right now that I'm going to throw up and then I'm going to faint. Thanks Ellen." he says at the end of the footage.
You can see the painful workout below.