Making my comment an answer then:
Jerry Pournelle's War World setting (which shares a universe with his CoDominion works and his collaborations with Larry Niven A Mote in God's Eye and The Gripping Hand) was opened to other writers for contribution.
The result was four collections of short fiction and a novel.
Most of the stories are set on Haven, but one takes place on Tanith (higher than standard gravity) and several feature exiled natives of another high gravity planet. Many stories also feature Sauron Supermen. On top of that is an overarching theme that Tanith is a forge in which humans are bred for improved combative fitness.
All together this gives us several groups of physically high-performing specimens to write about.