Chris Froome and Sky respond to inhaler video

Chris Froome has used an inhaler for his asthma since he was a teenager, said Team Sky in response to a Twitter storm that brewed overnight. French TV filmed the Critérium du Dauphiné race leader puffing on an inhaler yesterday en route to winning stage two to Col du Béal in emphatic style.

The team said that Froome's medicine is approved by cycling's governing body, the UCI, and does not require a therapeutic use exemption (TUE). The inhaler Froome uses does include Salbutamol, a threshold substance which is permitted to a maximum level of 1,600 micrograms over 24 hours. One puff usually equates to 100 micrograms.

The Tour de France champion used it in yesterday's hot stage, in which he attacked several times on the final climb and defending his race leader's yellow jersey. The television camera showed him puffing on his inhaler with 19 kilometres to race. He coughed often after the stage during interviews.

"I do have exercise induced asthma." Froome said after stage three. "I don't use [the inhaler] every time I race, normally only when I have a big effort coming up. It's a bit of a surprise everyone is talking about it."

"Given sports history, people are obviously looking for a reason. There's no reason to make a big deal out. It's completely allowed by the UCI and I have done all my tests for my asthmatic problems, and it's completely allowed by the UCI.  A lot of people see the interviews, I'm coughing afterwards, that's one of the reasons, the narrowing of my airways."

The image stirred up several messages on Twitter. His girlfriend Michelle Cound responded and echoed what Sky said this afternoon, that Froome used it since he was "a kid."

Cound wrote, "No TUE required, he has asthma, hence the coughing after exertion #duh #trolls"

At last year's Tour de France, Froome said that TUEs are "rather personal" and that he did not have any.

Many athletes  have TUEs for salbutamol (the active ingredient in some inhalers) due to exercise-induced asthma (a condition that can be brought on by excessive or intense exercise). In 2008, Alessandro Petacchi was banned for over-using his asthma inhaler. Testers found excess levels of Salbutamol in his system, which Petacchi said was due to human error or too many sprays during the day.

The UCI's rules say that the requirement of a TUE depends on the drug which is used to treat asthma. You do not need an exemption for Salmeterol (up to a daily dose of 1600 micrograms) and/or Formoterol (up to a daily dose of 54 micrograms). Terbutaline requires an exception.