[icebraining]

Jumping from airplanes didn't require any changes to biology, even with much greater falls.

[philh]

I believe ericd is talking about the ascent, not the descent.

If you want to jump over a building, you need to depart the ground at the same speed as you'll hit it on the way down (more, because of air resistance). The forces applied to your body are just as lethal in both directions.

(This specifically applies to jumping, where all your acceleration comes at the beginning of the journey. Jetpacks, planes, etc. get around the problem by letting you accelerate while in midair.)

[icebraining]

If you want to jump over a building, you need to depart the ground at the same speed as you'll hit it on the way down

Well, the horizontal speed can be gained more slowly (running before the jump). Only the vertical speed needs immediate acceleration.

[ericd]

Yeah, it's just that the vertical is much more than enough to kill you (more than the energy from jumping off the top of the building), so the horizontal is kind of irrelevant.

[ericd]

Yep, thanks for clarifying, I was talking about the jumping portion.