Curious to know how celebrities squeeze fitness into their daily lives? Want to know the secrets of the stars? Bi-weekly our That's Fit fitness expert Fitz sits down with the celebs we want to know more about, and digs out their great and not-so-great methods to staying healthy.

Picture the Hulk with dreads, and a giggly personality. That's Brad Johnson. Brad Johnson is the superhero character on Discovery Channels' Last One Standing. Funny thing is...he IS his character. The man who topples competitors with his mantra "I'm Brad", is straight out of a Marvel Comic. He is a 29 year old father of two from Oklahoma, and one of the most successful lightweight Strong Men in the United States. Don't let that confuse you though. Brad is massive, but his 236 pound body comprised of pure muscle falls under the 240 pound criteria for Strongman heavyweight status.

Discovery Channel thought it would be fun to grab three American athletes and three from the UK and pit them against each other in ancient competitions amidst third world tribes. The competitors live with the tribes, eat what they eat, and train for battle in these ancient games.The competitors travel to Kalapalo, Brazil (wrestling); Zulu, South Africa (stick fighting); Tarahumara, Mexico (endurance running); Mongolia (wrestling); Trobriand Islands (tribal cricket); Sumi, Nagaland (Akikiti kickboxing); Senegal (wrestling); Papua, New Guinea (canoe racing); Brazil (Kraha log racing); Peru (glacial challenge); Java (martial arts); and Vanuatu (canoe racing).

Brad and I spoke last week about his wild trip around the world. He's passionate about sports and fitness, a fierce competitor who is willing to talk himself through anything with his "I'm Brad" mantra, a dedicated family man, and also a lot of fun. I called him giggly, but that's probably not the way his competition perceives him. Lucky me, to simply be on the other end of a conversation hearing about his exciting adventures. The Last One Standing airs Thursdays at 8:00 pm on Discovery Channel.

Fitz: What does "I'm Brad" mean?

Brad: It's my way of saying "of course I can do this!". I'm Brad! When I say that, I live up to my own expectations of excellence. Brad can not be stopped.

Fitz: How did you get into Strong Man competitions?

Brad: I played sports as a kid, football, track, and power lifting. I still wanted to compete after high school was over, so I pursued power lifting. I did really well, and basically got bored with it. Strong Man looked more interesting, power lifting only consists of three basic lifts. It also was exciting to finally be challenged again.

Fitz: What was the transition like?

Brad: Awesome! The power lifting competitors were really cocky and annoying, but all of the Strong Man competitors were helpful and positive. It was strange! Instead of trying to screw with me, they were giving me pointers and cheering me on. I loved it!

Fitz: How did you get involved with Last One Standing?

Brad: Discovery was specifically looking for an American Strong Man competitor and the American Strong Man Federation recommended me as a good candidate. A couple of weeks later I was auditioning in New York. It consisted of a three hour miserable boot camp. I think they chose me because even after my legs locked up on me two hours and 45 minutes into it, I came back and finished the training. They must have thought I was psycho enough for the competition. It was brutal.

Fitz: And then what happened?

Brad: Within a few weeks, I was granted a passport (never been out of the U.S. before) and flew off to visit some of the wildest tribes in the third world. I was only supposed to be gone for eight to nine months, but Discovery thought it was going well. We ended up extending the show to 12 episodes which took 14 months to shoot. I'd come home for a week every few months.

Fitz: You did some pretty important work on one of your breaks.

Brad: Yep! My wife and I conceived our second daughter, Jasmine. Big sister Amethyst is glad we did.

Fitz: Congratulations to both of you. A future adventurer, I'm sure. What was it like living with the tribes?

Brad: It was great. I think most of the people were a bit leery of us at first, but when they discovered we were eager to learn about their customs and their athletic competitions...they treated us like family.

Fitz: What was the toughest competition?

Brad: Running a marathon through the mountains and cactus bushes of Mexico wearing these ridiculous little 'tire sandals' was excruciating. We literally cut a sole out of a tire for the bottom of our feet and then strapped it on with string. It hurt so bad.

Fitz: How far was the race?

Brad: Longer than a traditional marathon.

Fitz: How long did it take for you to finish?

Brad: I didn't. I locked up and about died at mile eight. I used to think I could do anything I told my body to do. Apparently I was wrong.

Fitz: What was the easiest competition?

Brad: Nothing was easy!

Fitz: What was the scariest competition?

Brad: I never was really scared of our physical tasks, but the food was pretty freaky. I ate every last bit of sheep: testicles, intestines, you name it! And then we were served both cat and dog in Nagaland by the tribes. I had gerbil in Peru as well.

Fitz: Yuck! I'd rather starve. What did they taste like?

Brad: Cat tasted like wild animal; really "gamey". Dog tasted like pork though. The gerbil was just weird.

Fitz: Were you injured at all during the competitions?

Brad: Yes. I broke a few fingers, and separated my shoulder wrestling in Mongolia.

Fitz: Like wearing the loin cloths? You look great in them!

Brad: Thanks! And yes. I enjoyed the wardrobes. The banana leaf palm was my favorite. One of the guys actually got third degree burns on his butt while wearing the banana leaf.

Fitz: What did you think about the health and fitness habits of all the tribes?

Brad: Mostly, they had horrific eating habits. Everything was cooked in grease. Everything! But they worked out so much while training for their competitions, they had awesome physiques.They had makeshift gym equipment too. I thought it was great that they were at least trying to lift, so I showed them some techniques for safety. We all got along great.

Fitz: If you were on a Dancing with the Stars style competition with the rest of your Last One Standing competitors, who would win?

Brad: Either me of the British kickboxer Mark.

Fitz: What's your favorite healthy food?

Brad: I love slow cooked chicken with barbecue sauce and whole wheat pasta.

Fitz: What's your favorite not so healthy food?

Brad: Klondike bars!

Fitz: What's on your MP3 player?

Brad: Linkin Park, Rage Against the Machine, and Gnarls Barkley.

Fitz: What's your favorite vacation spot and do you work out on vacation?

Brad: I love Vanuatu Beach in Australia. And yes, I always make a point of exercising wherever I am.

Fitz: Any advice for the general fitness buff trying to get in better shape?

Brad: Yes. The food you put in your mouth is 60-70% of the deal. Eat right. Treat your body like a Lamborghini. You wouldn't put cheap fuel in that car...you'd put in the high octane stuff. Treat your body the same way, like a precisely tuned machine. Treat food like fuel!