When our body doesn't get enough oxygen, we can become tired and lethargic. We may have difficulty breathing and moving. If the problem is severe enough, we can become dizzy or lose consciousness, and for extreme cases it can lead to death.

You use up your energy because you are moving you body.

https://docs.google.com/a/gsiscommunity.kr/presentation/d/1vDaBsJjoM8SWTLNFQ1-PBiXfqexB89OgyczlCBgyVPc/edit#slide=id.g8cdfbc36_0_12
Kevin and Changhee

Breathing is a constant process where you breathe in and out constantly through out the day. It is a process of taking in oxygen and expelling carbon dioxide, but respiration is a process where the body breaks down the oxygen, so that the cells in the body can use it.
Respiration= sugar + oxygen = carbon dioxide + water + energy
Breathing= C6H12O6 + 6O2 = 6CO2 + 6H2O + (Energy)