Physiology, that is the study from the chemical and physical point of view of the internal processes of living beings, is very useful to master to increase the quality of life.
It is partly transversal to the Food and Running section, since it is fished from the first to provide energy to the second (and not to be overweight at the next reintegration.).
Energy systems in the human body – How we produce energy
Macronutrients – Our fuels