BEND, Ore. -

Bend resident Chris Horner will not be defending his Tour of Spain title. He withdrew from the race Friday as the treatment he was receiving for bronchitis was deemed a health risk by his team.

Horner, 42, was given doses of cortisone after suffering bronchitis during the Tour de France and Tour of Utah, and had been cleared to race by the International Cycling Union.

However, his Lampre-Merida team adhered to the regulations of the Movement for Credible Cycling after he showed a cortisol level lower than the minimum recommended amount.

In a team statement, Horner said he was sad about the news, because defending his Vuelta title was his main goal this year.

He said his bad bronchitis had caused him a lot of problems, and he'd been suffering it for weeks.

Last year, Horner became the oldest-ever Grand Tour winner at 41 when he defeated this year's Tour de France winner, Vincenzo Nibali, for the title.

This year's race begins Saturday, and last year's Tour de France winner, Chris Froome, and the Giro D'Itali champ, Nairo Quintana are considered the favorites.