LOS ANGELES (CBS) ̶ A mom and her son will be sharing more than cards and flowers this Mother’s Day; they’re sharing a kidney.

Mike Gaw was one race away from reaching his goal: to run a triathlon on every continent. But when his mother went into end stage kidney disease, he suddenly faced a race against time. His mother needed a new kidney and mike decided to become her donor.

“Didn’t want to put him in danger, he said it wasn’t my choice. He really wanted to save my life,” says Cindy Gaw.

So a year ago mother and son underwent surgery. They affectionately called Mike’s kidneys Hans and Frans, and Hans was successfully removed from Mike and transplanted into Cindy. According to the National Kidney Foundation, Kidneys from family members are more likely to be good matches but there’s no guarantee.

While his mother recovered, Mike resumed his grueling training, wondering how his body would now respond. The general health and long-term survival rate for kidney donors is about the same as non-donors, but for Mike there was a concern.

“Getting dehydrated when you only have one kidney has more serious risk associated with it,” he said.

Dehydration slowed Mike down, but he did finish his final triathlon in Africa. Mike says racing without Hans was worth it because of the life and extra miles it gives his mom.

“After all she had given life to me it’s very rare that a child has a chance to give life back to a parent and I feel blessed to be able to do that.”

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