In extreme circumstance, contractions that recruit motor units in a muscle to are the most powerful, but they cannot be sustained for long periods of time.

Mitochondria produce atp, a high energy compound. atp is used for all sorts of enzyme-mediated reactions, such as making proteins/nucleotides/etc, certain compounds cross the cell membrane, muscles move, etc.  without this source of energy, a cell will die. it will not be able to repair itself, defend against pathogens, etc.

Go into your kitchen and get some water or coolaid and warm up at hot dog