The best way to celebrate your birthday? Giving back to a good cause, according to Fergie.
The singer, who turned 36 on Sunday, was on hand and ready to run for her hubby Josh Duhamel's charity race benefitting Japan that day.
But she did a fair share of celebrating in Las Vegas on Friday, where she partied until sunrise...
"He wanted to have the run on Saturday and I said 'Babe, that's not a good idea'," Fergie explained to E! News in Santa Monica, "My Vegas birthday was on Friday. We stayed up pretty late until the sun came up!"
Fergie and Josh had a blowout at The Bank nightclub, where she got surprised with a unicorn birthday cake.
Sounds like Josh, who hosted the race, might still be struggling from their Sin City soiree. When asked if he and Fergie would walk or run, he told us: "She'll be running. I'll probably have to stop to take a breather at the halfway point!"
Before the race started, Josh chowed down on a Fatburger, who were selling burgers with all proceeds going to the Red Cross.
"It's Sunday morning and it's raining and Paris and I are in our sneakers running," Nicky said. "I just can't imagine what they're going through right now and our prayers are with them," Paris added.
—Reporting by Marcus Mulick