Let's hope Adrian Peterson's refreshing take on the use of performance-enhancing drugs in the National Football League sets an example for his fellow players and the union that represents them.

Asked about blood testing for an NFL study that is expected to bring the league closer to a leaguewide screening process for human growth hormone (HGH), the Vikings star running back didn't hesitate.

"I like. I love it," Peterson said last week. "To be honest with you, I've been hoping that they did this a long time ago. To even out the playing field and make guys be honest and true to themselves. So I can't wait till they draw my blood."

The issue is personal for Peterson, whose amazing recovery from knee surgery and a Most Valuable Player season have fueled suspicions. Peterson says he wants any doubts erased. He also wants any drug-enhanced competitors removed from the game — and so should the players, owners and fans who have made the NFL the country's most popular sport and a multibillion-dollar industry.

We have our own doubts — about the union that represents Peterson. The NFL Players Association (NFLPA) and the league included HGH testing in their 2011 collective bargaining agreement, but implementation has remained as elusive as Peterson in the open field. The news that prompted Peterson's comments might represent some slow progress on the issue, although there is good reason to remain skeptical.

NFLPA representatives, including Vikings linebacker Chad Greenway, informed fellow players last week that they will soon be asked to give blood as part of the league's study. The results of the tests — which will include only numbered, anonymous samples and no disciplinary action — will provide the league with a baseline for "normal" HGH among players. The NFLPA has speculated that HGH levels might naturally run higher among players than the general population.

Meanwhile, it's unclear how long the study might take, or when the league and its players might reach a final agreement on testing standards and procedures.

Maybe the players who joined Peterson in voicing support for the study know any real testing is years away, but nevertheless their willingness to go public on the issue is positive. They should also be lobbying NFLPA leadership to work with the league to fast-track testing.

To his credit, Greenway said the union wants a "clean league." But until the NFL and NFLPA agree on a credible HGH policy that includes strict enforcement protocols, suspicions will linger that something other than weightlifting and protein shakes is making players faster and stronger.

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An editorial of the Star Tribune (Minneapolis). Follow the editorial board on Twitter | Facebook | Pinterest | Google+