ESPN NFL Insider Field Yates explains why age may not affect Adrian Peterson the way it does to most running backs over the age of 30. (1:28)

HOUSTON -- There's little doubt in the minds of Minnesota Vikings running back Adrian Peterson or his trainer James Cooper that the NFL's reigning rushing champion can do it again this year at age 31 or play long enough to break Emmitt Smith's career rushing record.

It's the toll of the NFL grind that could cause him to walk away, Peterson said.

In an interview with ESPN on Monday, Peterson said he believes his body will hold up as long as he wants to play. He needs 6,681 yards to break Smith's all-time rushing record, and even though only 12 players have ever surpassed 1,000 yards in a season at age 31, the running back isn't fazed.

The determining factor in how long he plays, Peterson said, will be how much longer he wants to go through the tedium of NFL life.

"That's it," Peterson said. "Training camp, going through the grind, OTAs and all that -- that will definitely be the deciding factor. Physically, body-wise, I'll be good. It's just mentally -- like with OTAs, I'm out there practicing, I'm going, I'm putting in work. But it's so repetitive that it's more suited toward the young guys and getting them into the system. It gets kind of boring."

When he is reminded how many times his old teammate Brett Favre seemed to come out of retirement right around a minicamp or training camp was over, Peterson joked, "I might have to try that."

"Think about this: The 2012 season [after recovering from ACL surgery], I didn't do any training camp. But I was over there on the side, working out. You get that extra month of working out? Come on, man. I would much rather not participate in training camp and work out, just to have more of an edge. Training camp, you're going out there, you're playing football, you're going to lift, and after that, you don't want to do anything. You're tired, from meetings and all that."

Then Peterson said with a laugh, "I don't know -- maybe in my next contract we can work out something like that."

The running back is far from the first veteran to tire of training camp, but Peterson said his eyes were also opened during his suspension last season, when he had more time to be at home with his wife, Ashley, and his son, Adrian Jr.

Peterson was suspended by the NFL in November 2014 after an investigation into Peterson's discipline of one of his children, which involved using a switch. Peterson pleaded no contest to misdemeanor reckless assault, had to pay a $4,000 fine and serve 80 hours of community service, and was reinstated by the NFL in April 2015.

A second son, Axyl, was born to the couple last September, and Peterson has four other children.

"All that could be a deciding factor for me, too," he said. "The kids and all that, that plays a role, because I love spending time with my kids, and they're getting older now. We'll see how things play out. I think you just have to wait for that time to come, and it will feel right or it will feel wrong. Right now, it feels good. It feels right [to be playing]."

Peterson and Cooper said that after Peterson returned from his suspension to lead the NFL in rushing at age 30, that age won't erode the seven-time Pro Bowler's skills.

"To the public, he's Adrian Peterson. He's this workout king," Cooper said. "But to me, he's just another number. He's literally someone who still hasn't reached his full potential.

"My suggestion to him is, he needs to retire when he knows he cannot put in the offseason he's been putting in. Once that offseason goes away when you're not motivated to work like that, that's when you get yourself hurt."