ASHBURN, Va. -- The aging running back didn’t act like one, producing the best season of his career. And then another. They represented the final acts of a Hall of Fame career and turned the Washington Redskins’ offense into one of the best.

The Redskins would like that to happen in 2018 the way it occurred in 1983. This time, it’s Adrian Peterson, 33. Thirty-five years ago, it was John Riggins, who had a career high in rushing yards at age 34.

Few can offer Peterson guidance for what he’s trying to do as the Redskins' every-down back. After all, Peterson already has rushed for more yards than all but 11 players in NFL history.

But Riggins managed his best seasons at ages 34 and 35. No player has rushed for more yards at those ages than Riggins. Only four backs have rushed for more than 1,000 yards at age 33 or older.

Riggins' run actually started in the 1982 postseason when, at 33, he topped 100 yards in each of the Redskins' four games. He clinched the Super Bowl victory over Miami with a 43-yard touchdown run.

In 1983, Riggins rushed for 1,347 yards and 24 touchdowns -- then an NFL record -- for the eventual NFC champs. The next season, at 35, he ran for 1,239 yards and 14 touchdowns. He retired after the 1985 season.

Riggins declined to be interviewed for this story, but he told the crowd at the Redskins’ Welcome Home Luncheon last month, “I kid around and stuff, but I had as much talent for a running back as anybody that’s ever played this game, and I say that in all humility.” Before the event, he met Peterson and told him to “be confident in who you are.”

“This was a big guy who ran fast,” said Charley Casserly, the Redskins’ assistant general manager during Riggins’ time. “He was a rare athlete. Peterson is a rare athlete.”

Riggins carried an off-field persona that didn’t jibe with his on-field work. Even now, Riggins jokes about falling asleep in meetings, saying he did so because he was tired from carrying the ball so much.

But former Redskins tight end Donnie Warren, a longtime scout with the Carolina Panthers, said Riggins would run 10 100-yard sprints at the end of practice, adding one more each day when they were in camp.

“We’re going out having a couple beers and this guy was running 100-yard sprints on a field to get ready,” Warren said. “He was in phenomenal shape.”

Former teammate Joe Theismann needed about one second to come up with an answer as to why Riggins produced so well at that age.

“His work ethic. It’s simple,” Theismann said. “John was a hammer, and we would hit in practice. But he worked tirelessly on his craft and kept himself in great shape. He went as hard off the field as he went on it, but when it came to the end of practice, he knew he had to put in the extra time.”

But as he aged, Riggins was more off-limits in practice. Theismann recalled a time in 1982 when then-rookie linebacker Larry Kubin popped Riggins in a goal-line drill.

“Larry knocked the crap out of him,” Theismann said. “Everyone was like, ‘Whoa, you don’t do that. That’s the bell cow.’ It didn’t happen again, I can tell you that.”

Riggins was fortunate to play for a Hall of Fame coach in Joe Gibbs and run behind the famed Hogs offensive line. Warren, a blocking tight end, said Riggins helped them look good, too, with his power. Riggins was listed at 230 pounds when he played, but Casserly said he weighed at least 240. Riggins also was a former track star.

“Speed is probably one of the first things to go,” Warren said. “John worked so hard at camp that his strength probably stayed pretty much the same. ... John’s game was all power as well as football instincts. He had the anticipation.”

There are differences between Riggins and Peterson. Before he turned 33, Riggins had carried the ball only 1,861 times, compared with 2,574 for Peterson. Riggins’ two heaviest-use seasons occurred at 34 and 35, when he carried the ball a combined 702 times.

And Peterson has dealt with more severe injuries, tearing his ACL in 2012 and meniscus in 2016.

“They have different styles and body types,” Casserly said. “John is much thicker, upper and lower body. John was more patient; he’d have a little hesitation and then go. [Peterson] is 100 miles an hour and an upright guy. John ran with a lower center of gravity and he took it to the defense. Peterson hits the hole hard and he’ll take a lot of hits. John would absorb hits.”

During that time, Casserly said, they didn’t worry about Riggins’ age.

“If a guy is playing well,” he said, “you don’t really get concerned about it.”