Dale Earnhardt Jr. is calling his decision to donate his brain to science a "no-brainer."

NASCAR's most popular driver tweeted his intention earlier this week. He said Friday he plans to pledge his brain to the Concussion Legacy Foundation. The group works with Boston University on research into chronic traumatic encephalopathy, or CTE, a degenerative disease that doctors believe is caused by repeated blows to the head.

Earnhardt says he was inspired by reading about three former Oakland Raiders who decided to donate their brains in honor of teammate Ken Stabler. The quarterback's brain showed signs of CTE. Soccer star Brandi Chastain, among others, also has pledged to donate her brain for research.

Earnhardt has a history of concussions. He missed two races in 2012 after two concussions in a matter of weeks.