When coach Chip Kelly took over as head coach of the Philadelphia Eagles, he introduced “sports science” to the players.

He still is in Year 2.

The notion of “sports science” revolves around nutrition, proper sleep, conditioning … things that will help keep players healthier.

The players who were with the Eagles last season are all-in with the concept.

“The guys who have been here have gotten used to what the pace is, what to expect,” safety Nate Allen told the Philadelphia Daily News’ Rich Hofmann. “That's normal for us. Playing fast is a normal pace for us. The rookies, it took a little while to get used to it. But now everybody's coming along … I feel healthy [in Year 2]. I feel not as worn out sometimes. When you get into this OTA regimen -- we just feel fresh every day and not as run down. We get the right rest and nutrition, and that all plays a big part in it.”

The Daily News reported that during the season, the Eagles had 14 players who started every regular-season game. That was more than any other NFL team.

“We put a huge emphasis with the Eagles on recovery,” center Jason Kelce told the Daily News. “I think that's one of the things that helped us stay injury-free last year, for the most part. A lot of that came down to luck, too -- it's just kind of the way it goes. But the organization and the strength and conditioning department puts a huge emphasis on rest. A lot of the things that bigger guys have problems with is sleeping right … They're big on making sure you're getting the right amount of sleep, eating right, hydration, all that stuff.”

Second-year safety Earl Wolff was injured at Green Bay in early November and missed a number of games down the stretch.

Now as a second-year pro, Wolff is a true believer in “sports science.”

“Honestly, last year I would do a little bit of extra work -- but not as much as I'm doing now,” Wolff told the Daily News. “When I say 'extra,' I mean staying after, getting a hot tub, getting a cold tub, stretching after every practice, doing core work after every practice. It's those things -- and, honestly, I learned that from the veterans. I watched them last year and I saw how their bodies were holding up, and I want my body to be the same way when it gets to that time.”