Coming off his first Pro Bowl season, Russell Okung is out to prove that the impressive level of play he established in 2012 will lead to a long and productive career in Seattle. The 25-year-old offensive tackle chose an unusual way to stay in shape this offseason, picking up mixed martial arts as a healthy alternative to kick slides and pass sets. Okung said he has taken up a regular regimen of MMA work in his hometown of Houston to help improve his quickness, agility and flexibility for the upcoming season. “There’s a place down in Houston called Elite MMA, and I just got into it,” Okung said during a conference call Thursday. “It really involves a lot of quick bursts, and you’re really maxing out your body in every effort. So I got into that. “It’s pretty fun. It’s really good. It’s the best way to try and kind of simulate line play, so I like it.” The Oklahoma State University product discussed another thing he’s working on during his spare time — his education. He’s one of 21 current and former NFL players who will participate in the first NFL Franchising Boot Camp at the the University of Michigan’s Ross School of Business from April 26-29. The participants will listen to presentations from business leaders and professors during the four-day camp. Carolina Panthers owner Jerry Richardson, who spent more than three decades in the restaurant business, is the keynote speaker. A marketing major at OSU, Okung said he worked at Subway, Burger King and Office Depot, plus other odd jobs growing up. “I can’t help but to think about life after football,” Okung said. “While I’m at this stage in my life where I have this platform and I have the ability to learn things, I have to take advantage of them. I don’t want to look back after I get done playing and say I didn’t work toward any goals.” Okung said staying healthy and improving his technique were the keys to his breakout season last season, along with the steadying influence of offensive line coach Tom Cable the past two years. Drafted No. 6 overall by the Seahawks in 2010, Okung suffered through two injury-plagued years. However, he stayed healthy in his third season, starting 15 of 16 regular-season games and both playoff contests. Okung gave up just one sack in 2012, although he was whistled for 13 penalties, second among offensive tackles in the NFL. “On top of being a great motivator, he’s a really great teacher,” Okung said about Cable. “He really forced me to learn the intricacies of the game and to be a real student of the game, and to really understand what’s going on.