By definition, the warming up are exercises that are carried out prior to the physical activity and that have as objective to prepare the organism for the practice of physical activity.
The bodily functions that increase with warming are:
1) Blood flow: increases during warming improving muscle and joint elasticity. This decreases the possibility of having an injury.
2) Body temperature: This causes the cellular metabolism to increase. It also causes vasodilatation that allows a greater supply of oxygen and nutrients.