The pump activity of 〖Ca〗^(2+) ion and myosin needs chemical energy of adenosine tryphosphate (ATP). The muscle gains ATP in three ways, which are phosphate (ATP). The muscle gains ATP in three ways, which are phosphate creatine break down,cell respiration, and fermentation. The phosphate creatine is a hight energy compound that is formed when muscle is in relaxed condition. It does not give direct contribution in muscle contraction, but the phosphate creatine can regenerate ADP into ATP.
Another source of muscle contraction comes from glycogen (muscle sugar) within muscle. Glycogen will be converted into lactasidogen. Then. The lactasidogen will be converted into glucose and lactic acid. The glucose produced will be converted into ATP through cellular respiration and fermentation. Look at the following Figure