Squats under load are pretty fundamental. Carrying a killed deer on your back, or stone, clay, or a mate or a child all require effective loaded squats.
Where is the rest of the movement, then? Why not pick a big bag of sand and place it on your back, walk around with it, and set it back down again?
Wouldn't our ancestors carry far less, maybe max 90kg, then people do today? It doesnt make sense to brutally punish your joints with much more than that for part of that action and completely ignore the other part of it.
Sandbag carries and farmer walks do just that :). As for the idea that you are brutally punishing your joints, I don't believe that to be the case. Controlled squats vs running? Yeah, controlled squats will be way better on the knee. I do weighted exercises regularly and have a marketed reduction in joint pain from before. A barbell squat with good form will not put undue stress on the knee joint and builds muscle that supports it. For me, the added muscle also removed my lower back pain. This also comes with the caveat that you need to stretch and mobilize too.
“Studies have shown that an ant can carry one hundred times its own weight, but there is no known limit to the lifting power of the average tiny eighty-year-old Spanish peasant grandmother.”
― Terry Pratchett, Reaper Man
