All the men from teens to elders looked like gym models. It never struck me until I was in my 30's - but really I have the body of a sick individual and the guy on the gym adverts is actually what the human body looks by design, not some sort of aspirational dream.
I've seen comments like this before, and they're valid, but I've also seen evolutionary biologists and/or anthropologists point out too that many if not most people who are wounded or sick die. So you're also seeing selection bias, where the healthy thrive and you don't see the unhealthy because they're dead.
OK, a relatively large percent of hunter-gatherers die due lack of antibiotics & other modern medicine. But gp isn't claiming it'd be a good idea to return to a full hunter-gatherer lifestyle. They're just observing that "this is what a biologically normal, healthy homo sapiens looks like". And if you go to the gym you might replicate that -- presumably without incurring the fate of short-lived hunter-gatherers.
This is literally the pics from the first page of results you've sent:
https://farm6.static.flickr.com/5262/5764935531_d03188cea9.j...
https://deeptimes.files.wordpress.com/2014/04/pygymy-dad.jpg
http://assets.survivalinternational.org/pictures/733/ind-jar...
http://4.bp.blogspot.com/-tCsETZIB-z4/T8tJBhujVjI/AAAAAAAAHv...
https://i.ytimg.com/vi/oD_KKvTaXNQ/hqdefault.jpg
(Plus a lot of the more exposed tribes have changed their lifestyles and are prone to all kinds of western influences).