This Troper went through high school with several people who fit this trope perfectly and subvert it.

The wrestling team - 99% of the wrestlers are really, ''really'' dim. But the ''epitome'' of this trope is one of the varsity wrestlers. He is 250 pounds of muscle and fat, incredibly strong... and gets abysmal grades in even remedial/basic courses and has done things like intentionally set fire to his own hand and "helped" in gathering firewood for a cookout by ''breaking twigs and branches'' off the fruit trees (apparently, he was not aware that fresh wood straight from fruit trees does not burn that well).

A female example - One of the girls on the lacrosse team was nicknamed "Canadian Bacon". She was ''very'' strong and ''very'' dim. Case in point, she got bored and started playing with fire...in her own bedroom. And she set the bedroom on fire. And she set fire to a tire, while it was still attached to her dad's car. She got decent grades in remedial classes, though.

Mostly subverted by the football players and the javelin/discus/shotput throwers. They were of average to above average intelligence but quite a few were definitely {{Genius Bruiser}}s.

The master of ceremonies for a playwriting competition this Troper took part in was exactly this. He is a dancer by profession, and is quite buff. However, he makes the stupidest and most inappropriate comments while hosting, and my theatre teacher told me later "he makes me feel so smart".

Subverted: This troper manages to be a highschool offensive and defensive lineman, while taking every college course in the school, and being National Honor Society President. I had a double take when I realized that.

Some of my Army drill sergeants would say, "If you're smart, you'll live longer. If you can't be smart, at least you can be tough -- ''and follow orders!''" They don't prefer DumbMuscle, but they can work with it; can't make everyone smart.