His 11th season was over, 174 NFL games in the books, and as he settled in for another offseason, Andrew Whitworth could feel every single one.

Bulging disks in his back. Torn labrums in his hips. At this point in the distinguished career of the NFL’s oldest starting offensive lineman, such aches and pains come with the territory. He jokes that he’s “day-to-day”. But when was the last time he felt honest-to-goodness 100 percent? He’s not sure. Six — no, seven years ago, maybe?

At his age, it would be understandable — if not expected — to concede to these pains. Most do, eventually. But last winter, as his Bengals contract expired and his first-ever free agency loomed, he stepped outside into the brisk mountain air to again start an offseason routine that’s kept him fresher than offensive tackles 10 years his junior … and more consistent than just about any lineman still strapping on a helmet.

Outside of his mountainside Colorado home, the 6-foot-7, 330-pound behemoth lineman strapped on snowshoes. Gazing up at the Rockies, Andrew Whitworth started hiking.

During a season in which he has chased down a defender on an 80-yard fumble return, outran linebackers to spring downfield touchdowns, and decleated unsuspecting defensive backs at full speed, teammates, coaches, and Rams onlookers, alike, have marveled at Whitworth’s uncommon longevity. They can’t help but wonder: How it was possible for a 35-year-old to dominate trenches otherwise dominated by twentysomethings?

WATCH: Andrew Whitworth leads the way

He swears no one specific method has led to this late-career success. There’s no Fountain of Youth hidden in his backyard, no diet of avocado ice cream or miracle acai berries or alkaline water he plans to hawk as elixirs of football agelessness.

Still, just shy of his 36th birthday, Whitworth is playing the best football of his life at an age that’s basically geriatric by NFL lineman standards.

Only seven offensive tackles in NFL history have made the Pro Bowl in their age-35 season: Willie Roaf (Chiefs), Gary Zimmerman (Broncos), Jackie Slater (Rams), Mark Tuinei (Cowboys), Forrest Gregg (Packers), Lou Groza (Browns) and Whitworth. Five of those seven are in the Hall of Fame.

Just one, Slater, made a Pro Bowl past age 35, but Whitworth, who turns 36 on Dec. 12, is well on his way to joining him. Unlike other members of that group, he seems to be playing better with age. According to Pro Football Reference, Whitworth’s approximate value (AV) has risen from 6.83 in his first five seasons to 12.6 in his last six. Last week, he had his 50th career game without allowing a quarterback pressure. He’s allowed just 11 total through 10 weeks of the season.

Which brings us back to the snowshoes. While others rested that first week of the offseason, Whitworth slipped them on day after day, put on headphones, and trudged up Beaver Creek Mountain. Along the way, he stopped to lift and hang-clean boulders. “Caveman-type training,” he calls it.

Even off the mountain, his training methods are somewhat unconventional. During the offseason, he seldom uses weights, in order to not overtax his body. He’s a huge believer in the power of yoga. He has tried Orangetheory, Crossfit, and MMA, and rarely do any fitness trends come around without him investigating. When weather permits, he plays golf as much as possible — often five or six times per week.

Herein lies the secret — if there is one — to Andrew Whitworth’s extraordinary durability. You will never catch him standing still.

“As an older lineman,” Whitworth says, “if you start to sit around, you get stiff. You get tired. Things start to set in. As long as I’m here living and breathing, I’m going to be moving.”

FINDING RESPECT IN L.A.

For the first decade of his career, Whitworth was happy in the same place. He loved Cincinnati and spoke of finishing his career there. But when his contract expired last offseason, the Bengals didn’t treat him like a veteran cornerstone coming off two Pro Bowl appearances. Their offer seemed to suggest the 35-year-old tackle was on the precipice of a steep decline.

“They weren’t even in the vicinity of any of the other offers,” Whitworth says. “At the last second, when they realized they were going to lose me, they bumped that offer up a little bit. But still, not even close. I think they took for granted the fact that a lot of other people would make me offers that would be tough to turn down.”

In Los Angeles, Whitworth felt that respect. In reality, it went beyond that for the Rams. With one of the worst offensive lines in football last season, they needed him. Desperately.

The team also understood the risk in signing an aging, 35-year-old offensive lineman. After he joined, Whitworth met privately with Reggie Scott, the Rams head athletic trainer, to formulate a plan for his training and maintenance.

Right away, Scott was stunned by Whitworth’s knowledge of his own body. “His plans were just as good as anything I’d thought about,” Scott says.

Soon, the Rams would see what that body could do. His strength and speed at the position were nearly unparalleled. In the open field, he blocked with the force of a Mack truck.

“He’s an amazing athlete,” center John Sullivan says.

“A genetic freak,” adds left guard Rodger Saffold.

But it’s his intelligence that has Scott raving. Whitworth has an uncommon grasp of “volume control,” he explains. He understands just how much activity he needs to prepare for Sunday, as well as how much he needs to “deload” between games. Much of the team’s sports science efforts focus on how to track and control this volume.

In Whitworth’s case, Scott says, “He was already a walking sports science study.”

They settled on a regular season plan that would allow Whitworth to take off Wednesday practices, giving him back-to-back days in the middle of the week without live reps. That strategy has worked wonders in keeping him fresh through 10 weeks of the season.

Even so, Whitworth is constantly searching for better fitness methods. His curiosity in that regard knows no bounds. This season, his Rams teammates convinced him to regularly use supplements — like protein and amino acids — for the first time in his career. He still refuses to use anti-inflammatories, and trainers know not to bother asking. “I’ve probably had one Advil in the last eight years,” Whitworth says.

That’s not to say he’s perfect.

“I wish he would follow my diet,” Saffold jokes. “But he’s from Louisiana, and he loves his sweet tea. He loves his coffee.”

Among his fellow Rams offensive linemen, Whitworth’s mastery of his own body is well established. In the film room, it’s become old hat to marvel at his feats of athleticism. There’s no sense within the organization that his dominance will meet its end anytime soon.

Though, no one here is willing to jinx that longevity.

“Looking at him, how he plays,” right guard Jamon Brown says, “you can’t help but think, maybe he’s got 10 more years in him. Who knows?”

SLATER UNDERSTANDS

The gold standard of offensive line longevity wore a Rams uniform for 20 seasons, from the years of Pat Haden at quarterback to Chris Miller.

Jackie Slater is the only offensive linemen ever to last two decades in the NFL, a record unlikely to ever be broken. From 1983 to 1990, Slater missed just one Pro Bowl. From age 35 to 38, when practice during the week was full contact, Slater miraculously started 60 of 64 games along the Rams line.

Then, halfway into his 18th season, “the injuries started coming,” Slater says.

Slater credits a longtime Rams strength and conditioning coach Garrett Giemont for lasting that long in the first place. For years, Giemont sought ways to “retard the ageing process” with Slater, teaching him less taxing methods for training in an era when few worried about such specifics.

“He was all about keeping an old guy like me healthy and playing and thriving,” Slater says. But by 39, there was little anyone could do. Slater’s body simply broke down.

That day will come at some point for Whitworth. He understands this. He’s planned for it, asking every trainer and nutritionist he’s met how he might transition out of the game one day. But as Slater sees it, there’s no reason, with a bit of luck, Whitworth can’t last just as long as he once did.

“He’s still amazing,” Slater said. “And hey in my 13th year, I went to the Pro Bowl. My 14th year, I went to the Pro Bowl. My 15th year, I went to the Pro Bowl. If the good Lord blesses him, and he doesn’t have any injuries, he can do that at that age, too. He’s capable.”

But the specter of luck — and its crucial role — is inescapable. Slater recalls several plays in which a few inches separated him from serious injury. One split decision, he says, can change a career, and in this sense, Whitworth knows he has been fortunate. Over the past eight seasons, he’s missed just two games — both following an offseason knee surgery in 2013.

So, as his 36th birthday nears, it’s fair to wonder how much longer the NFL’s oldest starting linemen can keep this up. When will his age catch up to him? Will it ever?

“He’s beaten all of the odds,” Scott, the Rams trainer, says. “I’ll never bet against him. Honestly, I might retire before him.”

At his introductory press conference last March, before he became a major catalyst in the Rams historic offensive turnaround, Whitworth was asked if he had designs on playing into his 40’s. He carefully considered the question.

“I don’t know, as a lineman, if that’s possible right now,” he said.

Perhaps the odds are too long, the obstacles too great. But at 35, in his 12th NFL season, Andrew Whitworth is already used to uphill climbs.