AP Pro Football Writer
MANKATO, Minn. (AP) -- Embracing the challenge has always been a part of Adrian Peterson's persona. Bring it on, the star running back has often said with a smile.
He set the NFL's single-game rushing record as a rookie for the Minnesota Vikings. His swift recovery from reconstructive left knee surgery last season included a jaw-dropping 2,097 yards rushing and the league MVP award. No matter how rare the feat he's asked about, Peterson will usually insist it's possible.
There's another test he'd eagerly take: for human growth hormone.
"I can't wait until they draw my blood," Peterson said Friday after the team's first workout of training camp.
The NFL and the players union have been working on an agreement for HGH testing procedures. Supplemental HGH is a banned substance that's difficult to detect. It's been used by athletes for what are believed to be a variety of benefits, whether real or only perceived, like increased speed and improved vision.
"To be honest with you, I've been hoping they did this a long time ago, you know, evening out the playing field and make guys be honest and truthful to themselves," Peterson said, later adding: "I'm all natural. I work hard. This right here, it's a test for me personally, that I know that, 'Hey, I'm clean as a whistle,' and other guys as well. And then, like I say, it'll bring some guys to the forefront and be like, 'Hey, I guess this is how this guy's been performing so well.'"
Peterson said he believes HGH use is not uncommon around the league.
"You've got guys out there trying to provide for their families, they're going to try to get that edge, get that advantage, especially if they're not worried about trying to get caught," Peterson said. "Yeah, it's being used."
Vikings defensive end Jared Allen offered a less skeptical view but echoed his teammate's encouragement of the testing.
"You like to think that everybody is playing clean and that we have a pretty solid drug testing system now with steroids, being random like it is, that it would discourage that kind of use," Allen said. "I'm not na
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