Adrian Peterson knows how most people see running backs in their 30s.

So he asked Washington Redskins legend John Riggins how he dealt with it.

“He was like, ‘I’m taking care of my body and I have that mindset of you still got it and that determination. Most importantly, playing real hard,’” Peterson said. “Those are some of the same things that keep me going. It’s always good to get confirmation from guys who have done it before.”

Peterson is confirming to everyone else in the NFL he’s still got it. His 236 yards are good for fifth in the league, only three players have more than his three touchdowns and the 33-year-old’s contributions are one of the biggest reasons the Redskins are 2-1 at their bye week.

Washington went into training camp hoping second-round pick Derrius Guice would take the majority of the carries and work in tandem with third down back Chris Thompson.

Guice tore his ACL in the preseason opener, the Redskins sought an answer and signed Peterson, who has so far been better than expected after injuries cost him much of last season.

“He fell into our lap at a critical time, we needed a player, and he was there for us,” coach Jay Gruden said. “He is everything as advertised.”

Peterson came advertised as one of the most prolific running backs in history, but someone who hadn’t put up 1,000-plus yards since 2015. His workout — where he gave the Redskins no choice but to sign him over Jamaal Charles and younger back Orleans Darkwa — was the first indication Peterson could still run “All Day” as his nickname suggests.

His 26 carries for 96 yards and a touchdown in the opener at Arizona gave way to a rough Week 2 when Peterson had just 20 yards on 11 carries behind a banged-up offensive line. Running for 120 yards and two TDs on 19 carries Sunday in a blowout of Green Bay didn’t just revive hope in Peterson, but opened up the possibility he could be the Redskins’ workhorse all season.

“I hope so,” Peterson said. “It felt good to get out there and get into a rhythm, establish and be physical and get some nice chunks. If it’s not broke, don’t fix it.”

Even the best running backs’ bodies break down typically at this age, and Peterson looked as if he was no different. He tore the meniscus in his right knee and strained a groin muscle in 2016 and had a season-ending neck injury in 2017.

The fact Peterson was off from last November until the Redskins signed him is a testament to his ability to stay in shape and reinvent himself.

“It definitely inspires me,” said Dalvin Cook, who succeeded Peterson as the Minnesota Vikings’ starting running back. “He’s just one of those backs that don’t come around too often: big, physical, can run fast, he’s starting to catch the ball. He’s just a different back, different mentality. You try to put yourself in his shoes, but sometimes you just can’t.”

Only Peterson knows how he feels 141 regular-season and playoff games into his career. As he continues to climb the all-time rushing list — he’s 10th and 227 yards back of Tony Dorsett for ninth place — he thinks less about the players he’s passing and more about how to prove doubters wrong about him.

“I can’t change people’s perspective and how they feel,” Peterson said. “People are still saying, ‘Hey, guys can’t do it over 30.’ The only thing I try to do is be an example to let people know that, ‘Hey, you can.’ You can break through the box. It’s all about your mentality and of course taking care of your body and having that faith.”