SOCHI, Russia (REUTERS) - Russian Olympic skicross racer Maria Komissarova was in a serious but stable condition on Sunday after breaking her back in a Sochi 2014 training crash and undergoing surgery.

The 23-year-old had a metal implant inserted on Saturday during a more than six-hour operation and surgeons said they would not know how successful the operation had been for three or four days.

"Everything will be done to treat her as effectively as possible and for her rapid recovery," the Russia Freestyle Skiing Federation said early on Sunday.

"Maria Komissarova's condition, as before, is serious but stable. But the night passed satisfactorily."

The doctors treating her will again consider when she might be moved elsewhere to continue treatment, the federation said.

Her father was due to arrive in Sochi from St Petersburg, it added.

President Vladimir Putin visited Komissarova on Saturday evening to wish her a rapid recovery and called her father by telephone after the skier told him he was extremely worried.

Komissarova suffered the injury during training at the PSX Olympic skicross venue at Rosa Khutor Extreme Park. She was taken to Krasnaya Polyana Hospital Number 8, which was specially built for the Olympics, where doctors decided to operate.

The 1,200-metre skicross course at Extreme Park is a medium-pitch slope which features cambered turns, gap jumps, drops and flat sections.

The skiers race down the course in groups of four in a test of speed, skill and aggression with the first across the line the winner.