The 27-year-old, who won the individual sprint world title in Hong Kong last year as well as a gold medal at the 2016 Rio Olympics, collided with another cyclist while training at Germany's Cottbus velodrome.
"We are shocked...," the German Cycling Federation said in a post on its Facebook page. "Kristina is being flown to Berlin and will be operated on there in (the) coming hours."
The federation also posted a statement on its website http://www.bdr-medienservice.de/nachrichten/trainingsunfall-kristina-vogel saying that Vogel, who has won 11 world titles in total, was in a serious condition.
"After her training accident at Cottbus velodrome, Kristina Vogel was taken to an emergency hospital in Berlin. She suffered serious spinal injuries and is in intensive care," it said.
(Writing by Christian Radnedge in London, additional reporting by Thomas Escritt in Berlin; Editing by Ken Ferris)
