Why do athletes need to prepare their bodies before competing? First of all, it is important to understand that playing or sporting events is an overuse of the body or abnormality from the usual human abilities, such as using calf muscles to run marathons. Normally we understand that strong muscles must be large, but if you notice in marathon runners, calf muscles are even relatively small, why run longer than people with large calf muscles? In other words, muscle tissue has different physiological characteristics. Large muscles usually work in a way that exerts a lot of energy and is instantly fast, but it is quickly exhausted. However, small muscles are muscles with tissues with more blood vessels and oxygen content. Therefore, it can work longer and more durable, such as deep spinal support muscles, etc.