Will diluted urine tests shake up NFL draft?

Michigan safety Jabrill Peppers and Alabama linebacker Rueben Foster, who are both projected to be selected in the first round of the NFL draft, have flunked their NFL drug test for having diluted urine.

Peppers’ agents contend that he was heavily hydrating, drinking eight to 10 bottles of water a day, at the combine because he flew in from San Diego and had to work out with the linebackers and defensive backs. They noted that he never failed a drug test at Michigan.

Foster also forwarded a hydration defense.

NFL teams will have to make a decision soon. The NFL draft is set for Thursday through Sunday in Philadelphia.

Both claims may be medical plausible.

“There is no question in the field of doping control that one of the things that has be done when you give an urine sample as an athlete, the athletes are working hard and losing fluids,” said Dr. Bert Mandelbaum, an orthopedic surgeon and co-chair of medical affairs at Kerlan-Jobe Institute in Los Angeles. “They are drinking a lot and rehydrating. Their urine gets very dilute. There is a limit below which the sample is not good and it’s not acceptable. So, the dilute urine thing can be a very circular discussion in general for all athletes at all times because of that.”

Foster contended that he was rehydrating after a case of food poisoning.

"It's not common for athletes, especially when they are rehydrating to dilute their specific gravity," Mandelbaum said. "That's the metric that we use. When the specific gravity goes below a certain level, when it gets below that level, it's a threshold below which the samples have to be re-tested. The problem that you get into is that each sample after that gets even more diluted. It's almost impossible to concentrate your urine, once you're that diluted."

Pursuant to the NFL’s substance-abuse policy, a diluted urine sample is treated like a positive test.

“They could test them the next day,” Mandelbaum said. “Whoever is doing the testing can make that judgement when they should test them again.”