Castro qualified for the Colombian squad, along with Andrés Jiménez Caicedo and Sergio Salazar, in men's BMX cycling at the 2008 Summer Olympics in Beijing by receiving one of the nation's three available berths from the Union Cycliste Internationale based on his top-ten performance in the BMX World Rankings. Castro started his morning session by grabbing the seventh prelims seed in 36.301 seconds, but he could not match a more stellar ride in his quarterfinal heat with 14 positioning points and a fifth-place finish, narrowly missing out the semifinals by a single mark.