"My personal goal is to help inspire and motivate people to go out there," Sweeney tells PEOPLE

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Alison Sweeney is using her passion for fitness to help in the fight against cancer.

The actress, 39, is a fitness ambassador for City of Hope, a research and treatment center for cancer, diabetes and other serious diseases. In this role, she hopes to encourage people to get active to help prevent certain types of the disease.

“Leading a healthy lifestyle, having healthy nutritional habits and getting out there and walking and exercising does reduce the risk of so many different types of cancer,” Sweeney tells PEOPLE. “That is important information for people to know, that it’s not just about fitting into a pair of jeans.”

Sweeney is passionate about her work with City of Hope because she has seen the devastating effects of cancer firsthand.

“I have a history of cancer in my family,” she says. “I’ve lost lots of loved ones and then also have survivors. It’s just such a difficult disease, and to know that City of Hope is out there making a difference, trying to educate people in what they can do to minimize the risk, is really important to me.”

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Through her work with the organization, Sweeney has met many people who have inspired her.

“I’ll never forget the kids that I’ve met who have been impacted by cancer,” she says. “The beauty that you see in them, when they’re so strong and fighting through it, is just really overwhelming.”

To help raise funds for City of Hope, the former Days of Our Lives star has partnered with Arm & Hammer Truly Radiant for a social media initiative that encourages women to share their radiant moments on Facebook, Twitter or Instagram using the hashtag #TrulyRadiantFinish. For each photo shared using the hashtag, Truly Radiant will donate $1 to City of Hope.

“My personal goal is to help inspire and motivate people to go out there,” says Sweeney. “Every day, just do one more little thing that makes a difference.”