In case you need any motivation to get in shape, check out Jenna Lee's interview this afternoon with 91-year-old Harriette Thompson, who set a world record by completing a 26.2-mile marathon.

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She did it in San Diego over the weekend, completing the distance in 7 hours, 7 minutes and 42 seconds. That's almost three hours faster than any other woman above the age of 90 and she's now the second-oldest woman to complete a marathon in the U.S.

In case that's not inspiring enough, Thompson is a two-time cancer survivor who recently had to undergo radiation treatments on her legs. The Charlotte native told Jenna by phone that she doesn't even have any aches or pains just two days after the marathon.

"I don't know what it is, maybe I just don't have any feeling anymore," she joked. Thompson just wrapped up her 15th marathon since turning 76. She explained that she started running marathons to raise money for the Leukemia & Lymphoma Society and has raised more than $90,000.

Jenna asked how Thompson stays motivated to keep running.

"I've never really been inactive except when I've had to be in the hospital when I had serious cancer. ... I enjoy exercising and doing things. And I practice the piano a lot, and that's a discipline that I think carries over into the running," said Thompson.

Watch the full interview above with Happening Now's "top guest ever," according to Jenna.

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