There’s a great story about Herschel Walker, who during his workhorse season as a freshman in 1980, was asked by a reporter if he was tired from carrying the ball so much. “No,” Walker replied, “the ball ain’t heavy.”

This pretty accurately reflects the sentiments of most elite running backs: Give ‘em the ball and let ‘em run. But the problem is that there aren’t many players like Walker, and such a heavy workload — Walker averaged 30 carries per game for his career at UGA — usually takes its toll.

All of which brings us to James Conner, Pitt’s junior running back who carried the ball 298 times last season en route to ACC Offensive Player of the Year honors. Connor was a special player in 2014, but the question remains: Can he repeat that workload and production again in 2015?

“I always say I'll do whatever it takes,” Conner said. “That's my motto for everything in life. I want to do whatever it takes to win. So yeah, the workload is fine."

Given his track record through two years at Pitt, it’s hard to doubt Conner. He has been spectacular. But the history of tailbacks who worked as much as he did in 2014 doesn’t necessarily paint an entirely optimistic portrait.

Over the past decade, there have been 26 Power 5 tailbacks who got at least 269 carries in a season — 10 percent fewer than Conner got in 2014 — who returned to college the following year. Three of those players — Conner, Ohio State’s Ezekiel Elliott and Utah’s Devontae Booker — did it in 2014. From the other 23, we get a sample of what it’s like to rebound from a workhorse year at tailback.

Of that group, there are certainly a few standouts. Bishop Sankey had 289 carries in 2012 at Washington then returned in 2013 and upped his yardage total by 30 percent. Darren McFadden was a Heisman finalist in 2006 with 284 carries, then came back in 2007 and did it all again. Just last year at Michigan State, Jeremy Langford built nicely on a 2013 campaign that included 292 rushes.

But those are the exceptions.

Of the 23 running backs in our sample, 19 of them saw a decline in their total yardage output the following year. Fourteen of them saw a decline of at least 10 percent. Overall, the group’s yardage declined by 24 percent the year after their workhorse season.

The funny thing about those numbers, however, is that their talent didn’t disappear. Overall, only five saw a sharp decline in their yards-per-carry, and the group as a whole actually was better on a per-carry basis — albeit marginally. The real culprit was that those running backs averaged 68 fewer carries in Year 2.

That reduced workload was rarely precautionary either. Of the 23 running backs in the sample, 15 missed at least one game, and the group overall missed 2.4 games on average.

Of course, there are caveats to this information. Many running backs with the heaviest workloads went on to play full NFL seasons the following year. And while injuries were common, there’s no way to directly tie the previous season’s workload to the next season’s injuries. What’s perhaps the easiest explanation is to simply say that elite seasons are hard to achieve, and doing it twice is even tougher.

For Conner, however, the workload did seem to take its toll — even during the season. After racking up 96 carries in a three-game stretch in September, Conner struggled during his next two games, averaging just 3.8 yards-per-rush and failing to score a TD. After a bye, he seemed to regain his strength, but after a dynamic 68 carries and 483 yards during a two-game stretch against Duke and North Carolina, Conner was quiet in the seasons waning weeks — including an 11-carry, 38-yard effort the following game.

Still, Conner thinks he’s in good shape for another stellar season in 2015 — though he’s taking an interesting strategy for a workhorse back.

“I’ve been losing weight, trying to take off some of this body fat that won't do me any good,” said Conner, who is down about 10 pounds this summer. “You need some of it for the position, to take hits and stuff, but just try to slim down, get leaner, get faster because I still have my strength."

Conner is strong, and adding a bit more speed to his repertoire could help him cut down on those hits and break a few more big runs. But the best-case scenario for Pitt is probably if the leaner, meaner Conner gets his touches at the most important times, but the rest of a deep backfield chips in often enough to limit his mileage, too.