D.J. Chark likes root beer.

Give him any kind of root beer, and the LSU receiver will drink it: Barqs, Mug, IBC, you name it. His favorite is A&W, but he likes them all — even the homemade root beers at the dive restaurants here in Louisiana.

He sometimes consumes more than a couple a day, alternating between root beer and his other bubbly favorite, Fanta Strawberry.

Those days are over.

“Now,” Chark said, “it’s water, water, water.”

Blame Matt Canada and his new quick-paced, shift-heavy offensive scheme. The new system is loaded with presnap movement.

Those moving the most are the receivers. The result of this movement is extreme exhaustion.

“The first two practices,” Chark said, “were deadly.”

LSU’s receivers weren’t out of shape, but they weren’t in the kind of shape for such a fast-moving offense. They made changes to their eating and sleeping habits and post-practice routine. Chark stopped drinking sodas, and he began to go to sleep earlier. Receivers now spend more time recovering in the whirlpool and getting massaged in the training room.

It’s all an effort to combat the physical exhaustion — and mental fatigue, too — that comes with playing in this offense. Receivers are running like never before, moving multiple times on nearly every snap — a Canada staple — before jetting down field for a route.

Every position group has experienced growing pains in Canada’s new scheme. Tight ends and fullbacks combine to form a new position (H-back). Quarterbacks are digesting new and quicker reads, and they’re learning longer play-calls. Offensive linemen have a new communication system because of all the presnap movement.

The receivers have paid what appears to be the highest physical toll. Remember, their last offense was a pro-style system with little movement.

“This is something new for them. It is more running for them,” said Mickey Joseph, LSU’s first-year receivers coach who ran speedy spread schemes in previous stops at Louisiana Tech and Grambling. “It’s a lot of running, a lot of running on them.”

How much running, exactly?

Chark leads the team in acceleration-deceleration rate. GPS-tracking devices, worn on each player's chest during practice, measure an assortment of variables, including acceleration-deceleration. Every time Chark begins running and then slows, that counts as 1oneacceleration-deceleration or, as Chark calls it, "accel-decel."

During an average practice, Chark’s count is “well over 300,” he said. Russell Gage and Drake Davis, the next two receivers in snaps, average in the high 200s.

“There’s a dropoff. The next player would be a DB,” Chark said. “They’d be at 180-something.”

Take one play for example.

Chark breaks the huddle, then races to his designated spot on the wide side of the field, along the left sideline.

One accel-decel. 

A shift is called. Tackles swap places, running backs become wideouts and Chark runs some 25 yards to the opposite side of the ball, positioning himself in a slot receiver spot.

Two accel-decels. 

A second shift unfurls. Tackles switch back, a tight end becomes a slot receiver and Chark returns to his original spot to the far left of the field, near the sideline.

Three accel-decels.

By this time, the play clock is down to 8 seconds. The snap must be coming, right? Not before Chark motions behind the line of scrimmage as the decoy on a fake jet sweep.

Four accel-decels.

The ball is snapped, and there goes Chark, turning up the field and finally crossing the line of scrimmage after running more than 60 yards behind it in a span of 15 seconds.

Tired yet?

“I’m sure that the receivers are pretty tired — especially because we’re pretty thin at that position right now,” quarterback Danny Etling said. “They’re getting a lot of reps at running a lot of motions and shifts and stuff like that. I think it’s been a big adjustment for them, as far as conditioning-wise.”

You don’t have to tell Chark.

He’s doing things he “wouldn’t have to do, usually, but now it’s like a necessity,” he said. One of those things: no root beer.

Another one: leading.

LSU’s receiving group is one of the youngest and least experienced on the team. Before last season, no current receiver had caught a single pass. Chark’s 26 catches last season are 16 more than the others have combined for their career.

The depth issue Etling spoke of is quite serious. According to the roster, the Tigers have the same amount of scholarship wideouts (seven) as they do walk-on wideouts.

Behind Chark, Gage is a converted defensive back who played his first year at receiver last season (all of his five catches came in one game). A redshirt in 2015, Derrick Dillon didn’t have a catch last season, and sophomores Dee Anderson (four), Drake Davis (one) and Stephen Sullivan (none) combined for five receptions during their true freshman seasons in 2016.

Midyear enrollee Mannie Netherly, meanwhile, was in high school three months ago.

“(D.J.’s) been a great leader,” Joseph said. “He understands this is him and Russell (Gage). They’re seniors. It’s their receiving corps.”

Chark’s spring is full of leading and learning, too.

The physical toll of Canada’s offense is only half of it. Chark explains.

“Coming in, you come out in one formation and you could shift or motion,” he said. “Wherever your alignment was at first, by shifting and moving, your assignment changes as well. I might have this route when I shift, (but) I don’t have that route anymore. I’ve got another route. You’ve got to know the whole offense basically, from a passing concept.”

And then there’s the speed with which Canada demands everything be done.

“ 'Bang-bang-bang' is something he says for just about any drill, any exercise,” Gage said. “He likes things done immediately, ASAP. It might not seem like it, but he’s big on tempo. That’s a big thing for him, which is good in any offense. He likes things up-tempo and he likes it fast.”

Breaking the huddle quickly is a new change for everyone, especially the receivers. After all, they have to run the farthest from the huddle to their positions. Canada admits to changing his tempo during a game, moving from slow to fast to slow to fast, but he’s almost always got presnap movement.

Whether it’s receivers, running backs or, even offensive tackles, someone is shifting or motioning to one side of the ball or the other.

“That’s a big part,” guard Will Clapp said. “Right when we break the huddle, everybody has to get down because right when we’re set, somebody is moving. Somebody is coming across the ball.”

You don’t have to remind Chark. He misses his root beer.

“I went from drinking sodas,” he said, “to drinking water all of the time.”

Follow Ross Dellenger on Twitter, @RossDellenger.