ENGLEWOOD, Colo. (AP) — You can rattle off all sorts of reasons C.J. Anderson is back to being one of the NFL's top running backs 11 months after a right knee injury cut short his 2016 season.

Marathon bike rides .

Improved O-line.

New power running scheme .

Better backfield competition .

Perhaps nothing explains his return to excellence as much as what he said at his locker this week.

"I'm back to playing undrafted."

No more satisfaction for having won a Super Bowl.

No more exhaling after signing a big contract.

No more challenging the plays that are called.

Hitting the bike trails around Denver has helped his cardiovascular conditioning so much so that he didn't even break a sweat on his 15-mile ride on his day off Tuesday.

You no longer see him tapping his helmet for a backup to come in and spell him for a bit.

"Just trying to push through, just trying day by day to stay in the shape that I want to be in," Anderson said. "And I've always said being on the field more presents more opportunities and I want to continue to keep that going."

In two games, Anderson has 199 yards and a touchdown on 45 carries and 43 yards and a score on four catches.

Not bad numbers for a guy who was in danger of losing his starting job to running back Devontae Booker when training camp began following the second-year pro's progression in Mike McCoy's new offense.

When Booker reported to camp, he mentioned during his physical that he still couldn't lift weights like he wanted to after spraining his right wrist at the end of OTAs in June.

Alarmed, the Broncos sent him for X-rays, which revealed a hairline fracture that needed surgery and would keep him out for two months.

Booker appears ready to return to the lineup, but it's clearly Anderson's job now.

Pushed by free agent Jamaal Charles and rookie De'Angelo Henderson, Anderson had a terrific training camp and insists he's not concerned about his heavy workload through two weeks.

"I'm good," Anderson said. "Good sore is always good. I don't count touches. I just play. And I try to keep my body and myself on a routine throughout the week so I can be just as fresh as I was last Sunday. The goal is to be fresh when I walk into Buffalo."

The Broncos (2-0) hit the road for the first time this season when they face the Bills (1-1) and their stout front seven that limited Panthers running back Jonathan Stewart to 40 yards on 15 carries last weekend.

Anderson has 49 touches so far and he scoffs at the notion he can't maintain a heavy workload.

"I'm 26 years old," he said. "So, I'm fine."

Just last year, Anderson had 47 touches through two weeks. But after rushing for 107 yards and a touchdown against Houston on Oct. 24, he showed up at work the next day with a stiff right knee that would require surgery.

That ended his — and, really, Denver's — season.

In the offseason, fans feared the chip on his shoulder was of the chocolate variety after seeing pictures of him a little heavier than usual.

His bike riding helped him take the pounds off and build up his cardiovascular conditioning.

"I do believe I'm in the best shape of my life," Anderson said. "I thought I started hot last year, but I am doing some things recovery-wise, to keep my body fresh and to keep my mind fresh."

He said he's learned from veterans Demaryius Thomas, Emmanuel Sanders and Aqib Talib, adding, "my life has changed a little bit financially so now I can afford some of those other toys that have helped those veterans stay healthy for 16 weeks."

He won't say what those toys are, however.

"I like to keep my secrets my secrets."

What is obvious is that Anderson is the perfect lead back for the Broncos' new and improved offense.

"He's a short and compact runner that can break tackles. He presents a small tackle surface. If you tackle him high, you go over the top. If you tackle him low, he bounces off," coach Vance Joseph said. "He is the perfect body type in my opinion to be a first, second or third down force for us."

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