In NEVER DONE, presented by Titan Fitness, Grant Mccartney, American Ninja Warrior and obstacle specialist, meets up with UNBREAKABLE people from all walks of life in gyms across the country to swap stories, training tips, and unpack what makes them unbreakable, on and off the race course.

Everyone who has ever called themselves an athlete or has accomplished an impressive physical feat (such as completing an obstacle course race for the first time) started their fitness journey somewhere. Some people just pure love hard work and dedication. For those people, committing to becoming a better version of themselves every day is the easy part. 

But for most people, there was a defining moment in their lives where innocent motivation became unwavering discipline. No matter how badly they want to skip a workout or how terrible of a day they've experienced, dedicated people get it done. While some people find excuses, these people lean in, accepting that while there are variables that they cannot control, they are capable of focusing on what they can control.

WATCH NOW: NEVER DONE, Episode 1 | NEVER DONE, Episode 2

These people — those that are truly UNBREAKABLE — have the power to uplift and strengthen everyone around them. They bring that grit, that iron, and that fire to everything they do.

Grant Mccartney and 'Spartan' Christos Giagos Take on a Spartan Race

In the third episode of NEVER DONE, presented by Titan Fitness, Island Ninja Grant Mccartney teams up with mixed martial artist and Ultimate Fighting Championship (UFC) Lightweight division fighter Christos Giagos in Southern California to get a glimpse at the dedication, commitment, and sheer hard work it takes to be the best in the game.

With three professional MMA titles under his belt, Giagos — nicknamed "Spartan" by former teammates due to his nationality — is no joke.

"You don't mess with guys with ears like [this]," he jokes while getting Mccartney set up to train, referring to the type of hematoma that many wrestlers and professional fighters have due to blood collecting in the outer ear after trauma to the tissue. 

Watch as Giagos puts Mccartney through the wringer before the duo tackles a CrossFit-style circuit workout together to prepare for their upcoming Spartan race together, where Giagos ends up putting on an incredibly impressive show of obstacle efficiency. You do not want to miss this Spear Throw-sticking moment. 

Watch the full episode above, and catch all of the new episodes on Spartan TV and YouTube. Then, sign up for a race of your own and show us what you're made of.