A curious fact about professional cyclists is the fact that a large segment of the peloton suffers from asthma. In fact, one study from UCSF estimated that half of Tour de France cyclists have the condition. Even more odd: Having asthma can actually lead athletes to a competitive edge. At least, that’s the case according to sports regulators who’ve prohibited some asthma treatments in sports.
Because asthma medications open up the lungs and their capacity to hold oxygen, more efficient respiratory function theoretically enables a more efficient athletic form. That thinking led the World Anti-Doping agency to restrict the use of numerous asthma treatments, known as beta-2 agonists, in 2002. Beta-2 agonists work by relaxing the muscles in your lungs, allowing your airways to open up. Meanwhile, other common respiratory treatments like glucocorticoids simply stem the lung inflammation that asthma can cause. Unlike beta-2 agonists, their use isn’t restricted in sports.
The distinction between treatments can be career-ending. Or, almost. In 2017, four-time Tour de France-winning cyclist Chris Froome was busted for doping. It wasn’t performance enhancing steroids that got him into hot water, but his use of beta-2 agonist salbutamol during a cycling race in Spain that year. Though Broome’s asthma diagnosis was well-known, responses to his claim that his use of salbutamol was mostly incredulous.
“Be prepared for explanations and excuses,” wrote Juliet Macur for The New York Times. After all, of all available asthma treatments, salbutamol is the one known to “increase endurance and increase lean muscle mass—basically the reasons the World Anti-Doping Agency affixed a limit to the amount an athlete could have in their system.” Froome, meanwhile, was at double that limit when he took a urine test during the race.
Still, the next year Froome was cleared by competitive cycling regulators. And even if Froome was inhaling salbutamol in bad faith, some sports experts contend that the limit-surpassing qualities of asthma medications are overhyped anyway. Dr. John Dickinson at University of Kent in the UK, who specializes in the effective sports have on the respiratory system, has said that only in “ridiculously high doses” would asthma treatment have the “potential to improve sprinting power.”
Further, evidence exists that in some cases, consistent exercise can actually cause asthma, which explains higher rates among athletes than the general population. But with a sport as rhythm-reliant as cycling or running, when winning and record setting requires straining ever further, even a small differential in lung capacity could become meaningful over thousands of breaths or pedals. In a bike race, every particle counts.