Are humans hard-wired for laziness and sloth?
I would have guessed that there would be a Gaussian distribution, but now I wonder about Pareto instead. The math of it is challenging for me, though. It's been a long time since I have used Functions.
Anyway, adult people do vary enormously in their energy levels, ambition, and physical determination. We all know that because it is obvious in the modern world wherein many people have choices of activity levels.
One thing that I am comfortable asserting is that a one hour workout daily (especially something like the Maggie's Routine) will increase your energy and drive to exert yourself. It works. Try it, if you disapprove of your slothfulness or lack of strength and physical endurance.