Simone Biles is giving back in a big way.
The bubbly 4-foot-8 Olympic gold medalist, born to a mother addicted to drugs and alcohol, was placed in foster care at the age of 3 before she and her younger sister could be adopted by their maternal grandfather, Ron, and his wife, Nellie.
“I was so young, I didn’t quite understand what was going on,” Biles tells PEOPLE. “But I recall some of the kids coming to the foster home with only the clothes on their back and a backpack.”
It’s memories like those that prompted Biles to partner with Mattress Firm Foster Kids, a donation-driven program that has given more than 610,000 items (like clothes and school supplies) to foster kids and their families.
“It was difficult,” says Biles of watching fellow foster kids come in without basics. “It’s hard going into the system with hardly anything, because even though foster parents may receive a stipend, sometimes it’s not enough to cover all the necessities.”
Founded in 2015, Mattress Firm Foster Kids is affiliated with 115 nonprofit partners across 40 states. The program holds six annual drives, and any items collected are given directly to foster children and families.
“This is such a personal cause for me,” says Biles. “Because I know firsthand what it’s like to be in foster care — struggles and all.”
For more on Simone Biles and Mattress Firm Foster Kids, pick up this week’s issue of PEOPLE, on newsstands Friday
The gymnast, who nabbed four gold medals and one bronze medal at the Rio Olympics, says she’ll attend as many drives as possible — and she can’t wait to meet the foster kids who will be receiving the items collected by Mattress Firm.
“I came from a foster home and went on to achieve everything I’ve achieved,” she says. “I’m just hoping it can inspire other foster kids to never give up and to always pursue your dreams. And to play sports and get good sleep!”
“My message is: There are no limits.”