Britney Spears Leads Charity Spin Class for Nevada Childhood Cancer Foundation: See Pics

Mario Lopez and Britney Spears
Denise Truscello

Mario Lopez and Britney Spears take a selfie before the charity cycle ride at XCYCLE Las Vegas.

The pop star helped raise more than a half-million dollars for the foundation.

On Thursday, Britney Spears took a break from her "Piece of Me" Las Vegas residency for a spin class -- and it was all for a good cause.

The pop princess joined fans for her "Piece of Me Charity Ride," benefiting the Nevada Childhood Cancer Foundation. Fans were able to score a seat in the spin class if they donated to the charity. Also along for the ride was Extra host Mario Lopez. Below, Spears and Lopez pose with XCYCLE owner Jen Barnet.

Denise Truscello
Mario Lopez, Jen Barnet and Britney Spears at XCYCLE studio in Las Vegas.

Before the class, Spears presented a check of $553,130 to NCCF president and CEO Jeff Gordon. She even took to Twitter, writing, "great way to raise money for some really cool kids!"

Spears also took time to meet sponsors and donors before joining Lopez for the 45-minute cycling class. The ride was part of the initiative by Spears and Zappos to raise $1 million toward building a new facility for the NCCF to provide critical services to young cancer patients and their families.