Why athletes use proteins?

Did you know...

Often we read about use of the proteins in physical activities that require muscle mass (eg bodybuilding). But why generally athletes need to supplement their diet with a significant amount of protein in different sports?

We consider few factors that can help us to better understand this increased demand of our body*:
 

1. Compared to a sedentary person, the athlete who practices physical activity has a greater muscle mass and a lower fat mass and requires a protein supplementation in the diet.
2. An intense workout that involves muscle mass results in a significant degradation of tissue compared with sedentary subjects
3. Athletes uses as energy sources, in addition to carbohydrates and fats, proteins to produce oxidative energy, in a percentage which increases according to the duration of the physical exercise that is related to a decrease in glycogen stores

*from "Alimentazione per lo sport e la salute di Pierluigi Biagi, Antonio Di Giulio, Amelia Fiorilli, Antonello Lorenzini"