Except they don't - heavier objects fall at the same rate (G - 9.8m/s^2) as lighter ones. You can experiment with this yourself - try rolling a ping pong ball and baseball down the same incline. You'll see they hit the bottom at the same speed (wind resistance is a thing, hence the incline, and you'll get more accurate results indoors).

Don't feel bad though - Aristotle got this wrong and it took until Galileo to get it right.

Don't take my word for it though, here's a Scientific American article about it from 2013: https://www.scientificamerican.com/article/bring-science-hom...

I'm pretty certain that was the GP's point as well, just expressed in a sarcastic tone. The experiment is famous for baffling physics students.

Obvious conclusions like exercise good and harder exercise better

And yet, the likelihood of heart issues follows a U-shaped curve against exercise frequency. So your conclusion would be incorrect

Except pushing too hard is also common sense to be a bad thing.