When he’s not helping people lose weight on “The Biggest Loser,” health and fitness expert Bob Harper is relaxing at home with his pooch Karl. He adopted the Havanese mix in 2010 and named him after fashion designer Karl Lagerfeld, who is known for his black-and-white ensembles, according to the Los Angeles Times.

Now in his 17th season with the hit reality competition show, Harper has been bumped up from trainer to host of the series, which airs Monday nights at 9 p.m. EST on NBC. This season, fans of the series get to see the contestants fighting off various temptations and working out in an updated state-of-the-art gym.

Before garnering fame with “The Biggest Loser,” the charismatic 50-year-old, originally from Nashville, worked as a certified personal trainer with celebrities like Jennifer Jason Leigh, Ben Stiller, Selma Blair and Gwyneth Paltrow, reported LiveStrong.com.

The tattooed physical fitness junkie – who recently worked with Michelle Obama on her Let’s Move! campaign – has written three No. 1 New York Times best sellers: 2012’s “The Skinny Rules,” 2013’s “Jumpstart to Skinny” and 2015’s “Skinny Habits: The 6 Secrets of Thin People.”

Headlines & Global News recently chatted with Harper about his best furry friend Karl.

How did Karl come into your life?
Karl is a rescue dog. He was found on the streets of Baldwin Hills [Calif.], all mangy and eating rocks, which breaks my heart to this day. So, when I first met him, I immediately fell in love with him. He was so scared and practically catatonic. All I did was feed him, hold him and love him, and now he is a brand new dog. [He has] so much personality, and is also very calm.

Are there any similarities between your personality and Karl’s?
Karl has a look in his eyes like he has got a million things going on in that brain of his, which is just like me. He also enjoys his own company, like me.

What does Karl do that makes you smile or cheers you up?
Karl can throw his own toys around and catch them and, when he does that, it just cracks me up. All of a sudden, out of nowhere, he flies across the room, grabs his toy and goes crazy. I just love when he does that!

Does Karl go to work with you ever and, if so, what’s it like for him?
I used to take Karl to work with me all the time, especially in the beginning because I never wanted him to be alone. But where I work, there are a lot of coyotes, so I don’t take him there too often and, when I do, I always keep him on a leash. He is great to run around with because he just stays by my side and never ever makes a fuss.

Does Karl like to watch his dad on television and, if so, how does he react?
Karl has been on TV a few times now, so he is a celebrity in his own right. As far as seeing me on TV, he has heard my voice coming from the television and it will perk his ears up.

For more on Bob Harper, visit him on Facebook, Twitter and Instagram.