Phil Pfister, winner of the 2006 World's Strongest Man competition, is out to prove there's some brains behind his brawn.

The Chesapeake Energy spokesman will appear Thursday on the popular Fox game show "Are You Smarter Than a 5th Grader?" matching wits with brainy children.

The show pits adults against kids on questions about math, science, English and geography.

The 36-year-old Pfister says he studied flash cards, visited the library and watched historical documentaries to prepare for the competition.

The former firefighter became the first American in 24 years to win the World's Strongest Man competition in 2006.