American cyclist Chris Horner has been competing at a far older age than most other athletes in his sport. Last year, he won the Vuelta a España at the age of 41, becoming the oldest champion of one of the three Grand Tour races.

He was preparing to compete in this year’s Vuelta a España again, but his plan was halted after his team—Lampre-Merida—replaced him with rider Valerio Conti. Age wasn’t the reason for replacement, but rather the strict anti-doping standards that come along with his team being a voluntary member of the Movement for Credible Cycling (MPCC), which is more stringent than the policies of the Union Cycliste Internationale (UCI).

Earlier in the year, Horner was authorized by the UCI for cortisone treatment to assist him in recovering from bronchitis. However, the treatment lowered his cortisone treatments to a level that was too low for the standards of the MPCC. While the UCI would have allowed him to race, his team’s requirements would not.

“Of course I’m sad about this news. I was willing to try to defend the 2013 title, Vuelta was my main target in the season, the team signed my with the aim of being competitive in the Spanish race, but I accept the decision linked to the MPCC’s rules,” he said in a statement. “This bad bronchitis caused me a lot of problems. I’ve been suffering [from] it for weeks and this treatment could have allowed me to solve the problem. UCI gave authorization for the treatment, I could race according UCI rules, but my team is member of MPCC. I understand it and we all must accept this situation without regrets.”

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