The notion of "spare time" has always been a relative term for heavyweight contender Shane Carwin.

The 6-foot-2, 265-pound father of two juggles a fulltime job as a mechanical engineer at the North Weld County Water District in Lucerne, Colo., with another as a professional mixed martial artist in the Ultimate Fighting Championship.

Today, while discussing his interim title fight with fellow heavyweight Frank Mir at UFC 111, Carwin said he's been given time off from his day job to prepare for the March 27 fight. But he'll keep the office gig as long as possible – or until other opportunities arise.

He likes juggling the two disparate careers.

"I take pride in when people ask me about the whole fighting thing." Carwin (11-0 MMA, 3-0 UFC) told MMAjunkie.com (www.mmajunkie.com) in an exclusive interview. "'Are you going to take time off? Are you going to quit your job?' I take pride in being a contributing member of society and going to work every day. It's something I love to do."

The biggest fight of Carwin's life is approaching, and he seems to be busier than ever. His calendar for Tuesday read something like this: work out, spar, and participate in the UFC conference call. Go to work for a few hours. Go to wrestling practice. Go home for a late dinner. Spend time with his family.

"Then I'll get up and do it again tomorrow," Carwin said. "That's just how my day is structured."

He said it's been this way since he began fighting professionally almost five years ago. There is little time to sit still, and none of it is spent without purpose.

In addition to his current duties, Carwin has a newborn daughter, Alexis, who is three weeks old tomorrow. His mother-in-law lives with the family and takes care of the baby in the wee hours to give him much-needed rest. But Carwin misses his daddy duties.

"In two weeks, I get to take over those responsibilities, and that's something I enjoy," he said. "I had the pleasure to stay up with her a couple nights. She's been a little fussy, and sitting in the rocking chair with her and falling asleep are things that I look forward to as well."

If healthy, the winner of Carwin vs. Mir will likely get a crack at heavyweight champion Brock Lesnar at UFC 116 on July 3.

Although he's doing the work of two people, Carwin won't go so far as to agree with UFC middleweight Chael Sonnen's recent statements that most MMA fighters are lazy. He has, however, come to realize there will come a point in which it's too difficult to manage his hectic life.

But thankfully, because he has two incomes, his priority is less based in security than what he truly wants to do.

"It's always been something that my wife and I have communicated about, and fighting is something I've chosen to do because I love to do it, and it's something I find fun and competitive," Carwin said. "We always said it would never be for money. That's kind of the same path that we've taken.

"If it becomes stressful on me and it doesn't become fun, I'll move on. I'll find something else that I can do in my spare time. There's things that I want to do in engineering, so I think there's other opportunities out there for me, too."

Eventually, he wants to start a business in water management. He doesn't want to work for the city forever, and he doesn't want to fight into his 40s.

"Our company is on the cutting edge of technology in mapping and engineering and hydraulic models that we've developed with a minimal amount of people," Carwin said. "We've gone around to conferences, and people have been amazed about what we've been able to do as a small water district."

That's a ways down the road, though. Despite wall-to-wall days of activity, he's having fun. Really.

"I just feel really blessed," Carwin said. "The family's expanding, and that's a good thing. My family are going to be the ones that are around the rest of my life, and that's exciting to me."