Eli5: How do apes like chimps and gorillas have extraordinary strength, and are well muscled all year round – while humans need to constantly train their whole life to have even a fraction of that strength?

Question

It’s not like these apes do any strenuous activity besides the occasional branch swinging (or breaking).

Whereas a bodybuilder regularly lifting 80+ kgs year round is still outmatched by these apes living a relatively relaxed lifestyle.

In: 8644

Answer 1

Some main factors. Avg human contains ~2/3 “slow twitch” muscle fibers and ~1/3 “fast twitch.” The great apes as you mentioned are basically the opposite.

Also, very important is the tendon insertion points of muscle groups. Iirc, joints are essentially fulcrums and the closer the attachment of a muscle to that joint will require more work and force to move the opposite end. Imagine holding a 20lb weight, if the tendon insertion of your biceps was closer to your wrist instead of your elbow, it would be much easier to lift. If you notice on great apes, their arms and legs never seem to be fully extended, their range of motion relative to our is pathetic, but they don’t need it like we do. Their joints/muscles basically come pre-loaded for work.

Another thing, is the size of their muscle bellies. Chimps are always hanging around in trees, that constant grappling strength can be correlated to a professional rock climber even in their fingers. Rock climbers muscles are extremely dense even they may appear scrawny. Which kind of answers the last part of your question…

Modern humans have to dedicate their lives to physical endeavors by choice, for great apes it’s all day every day from birth as a matter of survival.