Eli5: how are humans, who are two legged, able to out endure creatures that are four legged?

Question

Eli5: how are humans, who are two legged, able to out endure creatures that are four legged?

In: 1455

Answer 1

Depends on the human, because I can take my GSP/Lab mix on a 5k run and when we get back I’m literally dead and he still acts like he could run a 10k.