How do you personally use energy?

How do muscles use energy?

• As far as I know the glucose gets processed from carbs and fats and as a result carbon dioxide, water and "energy" are released. The carbon monoxide and water are expelled by the body, and then energy is used by the muscles. But how exactly is it used? What happens to this "energy" and what is it exactly?

• Answer:

  Muscles use energy by the Krebs cycle involving the molecules adenosine triphosphate (ATP) and adenosine diphosphate (ADP) in the mitochondria of the cells. https://www.google.com/#safe=active&q=krebs+cycle The mitochondria is said to be the site of cellular metabolism. Interestingly, athletes in high aerobic conditioning have a higher mitochondrial fraction in their muscle cells. This allows them to have higher metabolic throughput in those cells and put out muscular effort at a higher sustained rate.