It starts as a therapy session, but ends with Tom Aspinall and Joe Marler wrestling on the mat...

In between, Tom opens up about how he first got into MMA and what it actually feels like to know you're the best heavyweight on the planet - the mindset, discipline, and sacrifices nobody sees behind the title.

The conversation turns to retirement, and Joe shares his own experience of stepping away from rugby (three times), as they compare the hardest question in sport: knowing when it's time to stop.