Vikings star Adrian Peterson lives in Houston. While his neighbors crank the air conditioning on a June morning, Peterson leaves his house at about 8:30 a.m. and drives 45 minutes to meet his trainer at a workout facility featuring a sand pit, a steep hill and a track.

The burning in his lungs is assuaged by a simple and powerful thought: "I doubt any other running backs are doing this," he said.

Why does he? "I work with the mind-set of being the best ever," he said. "That, and my approach, set me apart. I have it in my mind that I'm doing things that nobody else is doing. You're not just saying you're going to be the best ever, you're putting in the work to accomplish that."

The work includes high-knee and shuffle drills, and running. "That's just the warm-up," he said.

Then he'll run eight 300-yard shuttles, comprised of 12 25-yard bursts. He'll run sprints, then shuffle, then backpedal, then backward bear-crawl — all uphill. He'll move to the sand pit to reprise those exercises.

''And once we're done outside," he said, "we go inside to lift." He doesn't get home until 3 p.m.

"When I say I want to be the best, I'm not talking about just running backs," he said. "I want to be the best player who ever played. I know I have a lot to do to get there. I know there have been a lot of great players before me. I think what I've done so far is pretty good, but I still have a lot of work to do to finish where I envision being when I walk away from the game."

This will be the last season Peterson plays before turning 30, the early-retirement age for many backs. He has rushed for 10,115 yards in seven seasons. Emmitt Smith holds the career rushing record of 18,335 yards. "Emmitt's all-time record is definitely something I will break," he said, nodding.

Peterson had just finished practice. He was sitting in full pads in a chair in a small room adjacent to the Vikings' locker room, speaking in a quiet voice filled with intensity, leaning forward as his eyes widened.

"I think breaking Emmitt's record will help, as far as stats go, in trying to become the best player of all time," he said. "But even though Emmitt has the record, I don't feel like he's the best back of all time. If I had to take him or Barry Sanders, I'm taking Barry every time. There are a lot of things that I factor in other than statistics."

Peterson challenges himself with numbers while remaining dubious of them. He said he's again setting his seasonal goal at 2,500 yards, but he learned that numbers aren't everything after his freshman year at Oklahoma, when he rushed for 1,925 yards.

"I finished second for the Heisman Trophy," he said. "I was the leading rusher in college football, and I didn't even win the Doak Walker Award [for best running back]. Cedric Benson won it. So I knew it was politics. I knew I was the best back that year, and the world knew, and that's all that mattered."

In recent years, Chris Johnson and LeSean McCoy have proclaimed themselves the best backs in the NFL.

"To each his own," Peterson said. "To be honest, and I told LeSean this, and Darren McFadden: If you don't feel like you're the best, you're cheating yourself. The catch is, you think you're the best back in the league? Well, I know I'm the best back in the league. They can put in the claim, but are they grinding like I'm grinding? I doubt it."

Peterson rushed for a career-best 2,097 yards in 2012 under offensive coordinator Bill Musgrave. He prefers memories of 2009, when he rushed for 1,393 but almost made it to the Super Bowl. This year, he'll play under offensive coordinator Norv Turner, who promises to use Peterson more as a receiver.

"I've been watching the offense the last few games, and it's like, 'Man, they don't even need me,' " he said. "Teams are going to have to play more honest. If they do stack the box, we'll beat them with the passing game.

"This is going to be the best offense I've played in. This is the offense I've been waiting for. We've got the pieces to facilitate moving the ball around. When Brett Favre was here, listen, when I saw those deep balls going up and guys making big plays, I was like, 'Yeah!' That makes your team very scary."

Peterson praised one of his former offensive coordinators, Darrell Bevell, now with the Seahawks. "This offense is going to be like night and day from what we've experienced in the past," he said. "Not to throw salt at the previous offensive coordinators — Coach Bevell was good, I have to give him credit — but Coach Turner has been doing this for 30 years. There aren't many offensive coordinators who can compare to him."

Peterson's ideal future would include "a couple" of Super Bowl titles, and no change-of-address forms.

"It's important to me to finish my career here," he said. "I really have a lot of respect for the Minnesota Vikings. I really didn't play much college ball, because of injuries. They saw something in me that those six teams that passed on me didn't see.

"It goes back to the combine, too. I never was that guy who was going to sell himself during a meeting with teams. I didn't say, 'If you don't pick me, you're going to regret it.' I just answered their questions. I wanted them to do their job. I thought the Vikings did their job. They selected me, and things have been pretty good so far. We haven't won a championship, but I don't think they regret the pick.

"I know it's a business. On the personal side, my goal is to finish my career as a Minnesota Viking. I would like to finish my career having played for just one team. Not many people get to do that. That would be special."

Jim Souhan can be heard weekdays at noon and Sundays from 10 to noon on 1500 ESPN. Twitter: @SouhanStrib • jsouhan@startribune.com