Three-time Olympic runner Dathan Ritzenhein returned home from London this week with his sights set on another big race: the Bank of America Chicago Marathon.

And he has some tips for marathon first-timers and veterans alike.

"Hopefully people have gotten in a lot of their training so far, but things always pop up, injuries and stuff like that," Ritzenhein told NBC Chicago. "You've just got to stay focused and stay excited for it every weekend, get out for those long runs and it'll be a fun experience."

The Michigan native represented Team USA in London and finished 13th in the 10,000-meter race on Aug. 10. Come October, he'll add 20 miles to his Olympic race.

"That's part of the big thing that I love is to inspire people to running because anybody can do it," Ritzenhein said. "It's an awesome thing, and the Olympics is such a big stage."

The Chicago Marathon closed its 45,000-runner registration in record time this year. The limit was reached in six days, 25 days faster than last year, which was considered a record at the time.