After racing the Ironman Triathlon World Championship in 1988, Peter Hanson stopped doing triathlons when he started medical school.

Last year, his close friend, Jim Owens, couldn't finish his training for Ironman Wisconsin when he was diagnosed with cancer.

Hanson was able to get his name onto the start list for the race in place of Owens, and raced in honor of his friend, and in order to raise money for the Lance Armstrong Foundation.

Hanson is back again, and like last year, he's raising money for the foundation.

Hanson says he'll be thinking of his friend a lot during the race tomorrow.

"When things get tough during the run, I'll say to myself 'If he can battle everything he's going through, I can get through this race."

Good luck, Peter … and all the best to you, Jim!