Froome has previously stated he has suffered from asthma since childhood and has used inhalers in the past. In a statement from the team, Froome explained that his symptoms worsened and he sought medical advice from the team doctor.
"My asthma got worse at the Vuelta so I followed the team doctor’s advice to increase my Salbutamol dosage. As always, I took the greatest care to ensure that I did not use more than the permissible dose," Froome said in a team statement.
"I take my leadership position in my sport very seriously. The UCI is absolutely right to examine test results and, together with the team, I will provide whatever information it requires."
The Vuelta race leader after stage 3, Froome was tested following the conclusion of each stage of the race. In the team statement addressing the finding, Team Sky stated that Froome "used an increased dosage of Salbutamol".
Addressing the finding, Team Sky principal David Brailsford explained the team will co-operate with the UCI to establish the cause of Froome's elevated concentration.
"There are complex medical and physiological issues which affect the metabolism and excretion of Salbutamol. We're committed to establishing the facts and understanding exactly what happened on this occasion," Brailsford said in the team release.
"I have the utmost confidence that Chris followed the medical guidance in managing his asthma symptoms, staying within the permissible dose for Salbutamol. Of course, we will do whatever we can to help address these questions."
As revealed in the 'Fancy Bears' hack, Froome and Team Sky previously applied for a TUE for the corticosteroid prednisolone in May 2013 and April 2014. In 2015 at the Tour de France, Froome explained that during the race he had a medical condition which could have been treated with a TUE. However, he objected to using a TUE, explaining in January 2017 that, "I didn't feel having a TUE in the last week of the Tour was something I was prepared to do. It did not sit well morally with me."
Salbutamol
The WADA threshold for Salbutamol is 1,000ng/ml. WADA rules state that a level above that “is presumed not to be an intended therapeutic use of the substance and will be considered as an Adverse Analytical Finding (AAF) unless the Athlete proves, through a controlled pharmacokinetic study, that the abnormal result was the consequence of the use of the therapeutic dose (by inhalation) up to the maximum dose indicated above.”
The UCI’s Theraputic Use Exemption (TUE) rules state that “Inhaled Salbutamol (maximum 1600 micrograms over 24 hours in divided doses not to exceed 800 micrograms over 12 hours starting from any dose) are not prohibited and therefore do not require a TUE.”
The UCI adds: “For inhaled salbutamol, you must obtain a TUE if you need to take more than 1600 micrograms over 24 hours in divided doses not to exceed 800 micrograms over 12 hours starting from any dose.”
A TUE is necessary to take salbutamol by any other route of administration.