Brawn means muscular strength. If the math team and the football team compete on field day, chances are the math team's brains will be less useful than the football team's brawn.
Stroll down the paper-towel aisle at any major grocery store and you'll encounter the paper-towel brand Brawny, featuring a well-muscled brawny man in tight T-shirt meant to promote the idea that Brawny towels are as strong as a strong man at a freak show—they absorb tough messes and will not tear.
