During the dog days of training camp, the Philadelphia Eagles tapped into a seldom-used part of Fletcher Cox’s skill set.

It had nothing to do with him holding the point of attack or leveraging his gap as an interior defensive lineman. Instead, one day after practice last August, the 6-foot-4 defensive tackle tested his luck fielding punts. The difference between Cox and the likes of Kenjon Barner, Darren Sproles and other punt returners? Instead of making calculated moves to avoid defenders, Cox would probably try to run directly through punt coverage, if given the opportunity.

The video the Eagles posted on Twitter of the end-of-practice shenanigans was met with a request from Cox. The sixth-year defensive tackle wanted to change his position on the roster to reflect the range of his football repertoire.

Philadelphia obliged, briefly altering the details of Cox’s bio to read:

91 -- FLETCHER COX -- ATHLETE -- 6-4 -- 310

It sounds funny to categorize a player of his stature and physique as an athlete, but it’s truly a reflection of the way Cox views himself. It’s part of a mentality he’s taken on with his offseason preparation to help him get to the point where he’s rarely coming off the field, raising his performance during the most critical stretch of the season.

He attributes the success he’s having with an even heavier workload in the playoffs to a somewhat unconventional training program he began five years ago back in his home state of Mississippi. In 2013, the Yazoo City native hooked up with Deon Hodges, a former wide receiver at the University of Southern Mississippi who was starting out his career as the head strength and conditioning coach at D1 Sports Training, the facility where Cox began putting in his offseason work after his first year in the NFL.

What Hodges saw was an opportunity to create a training regimen that went beyond traditional workouts for a defensive lineman. Cox wasn’t just going to spend his hours lifting weights, going through steer drills with other linemen or running through a three-cone setup to hone his agility and speed. Using his background as a skill player, Hodges designed workouts to fuse all of Cox’s tools.

“He’s just a natural freakish athlete,” Hodges said. “My job is to maximize it.”

At D1, Cox often trains with wide receivers and defensive backs. Hodges’ favorite piece of training equipment for his defensive tackle is a Vertimax, which is designed to increase vertical jump and first-step quickness.

For someone who has played every position from a zero to a five-technique tackle, Cox’s workouts reflect as much his ability as a hybrid defender as they do his capability to dominate whomever he’s going against.

“I’ll match him up in a bag drill against a receiver,” Hodges said. “We’re not going to use the excuse of he’s 200 pounds and I’m 315 [pounds]. Win the rep. That’s all that matters.”

There’s something about the fluidity to his movement that puts onlookers in awe, whether it’s taking on a double-team or exhibiting his strength in other nonconventional ways.

Hodges gets a laugh whenever Cox demonstrates something players of his size aren’t normally able to execute with such ease. There’s a basketball hoop inside D1’s training facility where Cox will often take $20 sucker bets between workouts from anyone who wants to see whether he can dunk a regulation-size basketball.

“He would go up and just tell them to keep the cash, go get yourself a nice lunch,” Hodges said with a laugh. “It’s almost like a side hustle. It’s hilarious to watch.”

The Eagles saw a change in their 2012 first-round pick shortly after Cox and Hodges began working together. Hodges flew to Philadelphia years ago to meet with Josh Hingst, the team’s strength and conditioning coach, who noticed a “different guy” when Cox returned for his second season in 2014.

“He does a really good job of making me uncomfortable,” Cox said of Hodges. “We’re doing drills that I normally don’t do as a D-lineman. I think those types of things stack up when it’s really time to go out and show that athleticism.”

Philadelphia’s defensive line has gone through as many as 10 different rotations of linemen this season, utilizing sequences during games to keep players fresh. During the regular season, Cox played an average of 59 percent of defensive snaps after missing two games because of injury. Leading into the playoffs, Cox began to see a spike in his workload. Against Atlanta in the divisional round, the defensive tackle played a season-high 90 percent of the defensive snaps, followed up by 79 percent against Minnesota.

“I think that they kind of took a big burden off my back,” Cox said about the Eagles' defensive-line rotations. “At first when coaches told me that, I wanted to be selfish and say no; I wanted to play the whole game, but at the same time I trusted them. The last couple games, I was playing 80 to 90 percent of the snaps where not playing 90 percent of the snaps early in the season keeps you from little knicks and knacks that linger the whole season.”

When Chip Kelly was coaching the Eagles, Cox was playing twice as many snaps because the Eagles’ up-tempo offense put the defense on the field more often. When Doug Pederson took over, the scheme changed. So did the workouts Hodges created for Cox.

“Now that you’re getting less reps, let’s be more productive,” Hodges said. “Let’s have a higher energy.”

An incredibly aware athlete with a relentless motor, Cox creates problems for offenses not only with his strength and range, but will often sniff out a screen and show off that athleticism by chasing down a receiver and making the tackle.

“I pride him on being that,” Hodges said. “The guy that’s going to go the extra effort and chase down -- we’re not just run-stop, clog up the holes, like we’re really going to be elite guys, and he buys into that mindset.”

As the Eagles aim to win their first Super Bowl, they’ll need to have Cox on the field as much as possible to generate pressure in a multitude of ways against Tom Brady. So much of that burden will be placed on the interior line, which is responsible for preventing Brady from stepping into the pocket, thus allowing defenders to come free off the edge and do their work in the backfield.

Philly’s 10 other defenders thrive off Cox being on the field. They know that if he’s able to handle multiple blocks, it creates more space for them to roam freely.

“Fletcher’s incredibly agile,” Eagles defensive tackle Beau Allen said. “He’s an athletic freak, too, so when you get that combination of work ethic and athleticism, it’s scary.”

Getting to the point where he can exert the same intensity on snap No. 1 as he does 53 snaps into the game and stay square to the line of scrimmage isn’t a rhythm built overnight. It’s a testament to the type of training Cox did months ago to put himself in a position where his best wouldn’t just be on display in the late weeks of the season -- it would reach its pinnacle in the biggest game of the year.

“The way that I’ve been performing in the playoffs, the way that things have been going for me, I would say that it’s a whole lot different from where I was during the regular season,” Cox said. “That makes guys around me a whole lot better. It just exploits their talent a whole lot better."