The sport of cycling has suffered another blow, in the eyes of the public at least, with a "non-negative" drug test from four-time Tour de France champion and Team Sky rider Chris Froome. It's worse still for Team Sky, which has been roundly criticised over now-retired Tour Champion Bradley Wiggins' use of a legal, but powerful and potentially performance-enhancing anti-inflammatory during his tour-winning streak. In Froome's case, it seems he's taken too many puffs of his permitted asthma medication, and that's pushed him over the legal limit.
In both situations, but unlike the fiasco of Russian athletics, neither athlete is being accused of taking a drug simply to improve performance. Rather, the implication is that the riders are making use of a personal health-related condition to use a drug that also happens to have performance-enhancing effects. In Wiggins' case, it was the powerful corticosteroid triamcinolone prescribed for his hay fever. In Froome's case it's salbutamol, a B2 agonist and the main ingredient of a common asthma medication.
If an athlete does need medication for hay fever, asthma, or any other health-related conditions, and that medication is on the banned list, they can apply for Therapeutic Use Exemption (TUE), which their doctor then signs. This TUE notifies the drug testers that they are allowed that drug.
The first question that needs to be asked about a TUE is whether the drug is really needed, especially if it also happens to have a performance-enhancing side effect. The second question is how much of that drug they actually need to alleviate the health-related problem.
A "non-negative" test result describes a situation where the athlete is shown to have a level of a TUE-permitted drug in their body that is far higher than expected, higher than would be the case if the drug was taken only for health purposes.