11.   U.S. skiers here, however, hope their altitude training and sleeping will pay off.

12.   Altitude training is natural for Philip Kimeli Boit and Henry Kimeli Bitok, who hail from the slopes of Kenya.

13.   However, red blood cells can also be raised naturally, for instance through altitude training.

14.   However, the red blood cell level can also be raised naturally, such as through altitude training.

15.   Later, he went for altitude training to Italy, where he lost a practice race to compatriot Erling Jevne.

16.   Reiko Tosa, a runner-up in both the Tokyo and Nagoya marathons last year, has yet to compete this season, focusing on the altitude training.

17.   She spent time in a chamber of nitrogen gas to simulate altitude training.

18.   The U.S. military defends low altitude training as necessary and says safety precautions are followed.

19.   While the other Norwegians continued competing, Daehli went to Italy for altitude training.

20.   Fossett was altitude training in Colorado but would fly to Australia once the Northam base was set up and weather was clear to go, the spokesman said.