Have you looked out your window lately? The entire planet is getting exterminated by your mellow Hippie Homo sapiens.
Skeletal evidence from Kazakhstan show that bodies and craniums of human - throughly MODERN humans - have been getting smaller and weaker over the last 8000 years, a quickening of the trajectory human physiques have been undergoing since they branched off from other apes.
Sapiens aren't so much contrastingly gracile as they are atrophying weaklings due to tool use, agriculture, and increasingly larger societies providing for all their needs. Cro Magnums may not have been as stout and barrel chested as Neanderthals, but they were significantly better built than humans today.
Bonobos are gracile, Chimps are more robust, Bili apes more robust still. Humans are de-evolving into spindly gelationous couch potatoes.