As many athletes do diving deeper into their careers, Kelley cut out processed foods, sugars and snacks from his diet, lowering his body fat from 18 percent last year to 13 percent this offseason. The running back can already feel the difference.
"I feel more explosive, faster, getting in and out of cuts a little better," Kelley said, via ESPN.com.
As a rookie, the 6-foot, 228-pound bruiser rushed 168 times for 704 yards and six touchdowns in taking over the starting role.
With Matt Jones headed out of town, Kelley heads into training camp as the starter, but will be pushed by fourth-round rookie Samaje Perine. Kelley knows he must diversify his game and remain in shape to keep the starting role past the preseason.
"It's hard not to say you don't feel some type [of pressure] when they bring another back in," Kelley said. "But it's the [NFL], someone comes in every year to try and take your job. If Samaje comes in here and does what he has to do, it's not his fault if he's playing better. I have to play better than him so I don't feel no type of way. It's all on me."