[Spoo]

Raapys said:
If you pick up a box and hold it for one hour then you've spent alot more energy than if you merly lift it up and drop it at once. Yet, the box doesn't have any more energy when it falls after one hour than it does if you release it instantly. So where did the energy you continously applied to the box for one hour go?

Your muscles require a constant use of energy to remain contracted. That energy ultimately "goes" into heating your body over the course of the hour that you spent holding the box.