Image 1 of 3 Theo Bos (Belkin) (Image credit: Sirotti) Image 2 of 3 Robert Gesink and team sprinter Theo Bos in the new kit (Image credit: Bert Geerts/dcp-bertgeerts@xs4all.nl) Image 3 of 3 Theo Bos (Blanco) has plenty to smile about after his sprint victory in stage 2 of the Ster ZLM Toer (Image credit: Bettini Photo)

Theo Bos has been cleared to return to racing, as Team Belkin's medical staff has rule that his low cortisol levels were caused by an asthma medication. He was prevented from starting the Vuelta a Espana after routine pre-race controls showed the low level. Bos will ride the GP Houtland on Wednesday, September 25.

Under UCI regulations, Bos could have started the race but the Movement for a Credible Cycling (MPCC) regulations force a rider with low cortisol levels to take an eight-day racing break.

The team medical staff and outside specialists looked at the case, and determined that there was no abuse of synthetic cortisoids, and that Bos was “extremely responsive” to his asthma medication.

“I’m very happy and relieved to know the exact reason for my low cortisol levels. When I heard I couldn’t race in Spain, I was really surprised,” Bos said in the team's press release. “The study’s results provide a clear story. Everything is clarified. We’re now going to look for another asthma medication.”

Team CEO Richard Plugge was equally happy with the news. "We are pleased that renowned experts have drawn a clear conclusion and that Theo is able to start,” he said. “We missed him as a good colleague and of course, in the last straight metres.”

Plugge added, however, that it was time for a consigns on the low-cortisol issue. “In the meantime, we have asked the MPCC to settle the international debate regarding the rule (to not start with low cortisol levels due to health issues) with international academic evidence.

“According to the UCI’s medical commission there’s no consensus between international medical experts on the subject. That’s why the UCI has not adopted the rule. The Dutch Doping Authority questions the rule, as well. Uniformity is of a major importance for cycling’s credibility.”