regular, constant and medium-intensity physical activity seems to help the immune system with a protective action on it?
On the contrary, a very intense sporting physical activity, protracted over time as for many endurance training and competitions marks the immune system leading to a weakening.
With moderate physical activity the immunological parameters improve, ie the lymphocyte response is better in defense against pathogens and phagocytic action by macrophages and neutrophils increases.
Already with a single session of physical activity there are numerous changes between the classes of white blood cells such as, for example, the increase in neutrophils and lymphocytes. This means that moving makes the immune system more active and, consequently, protection from possible inflammatory or pathological states.
When, on the other hand, physical activity becomes too intense, the concentration of lymphocytes is lowered, thus weakening the defenses to an immune depression