 During the study, the patients pedaled a bicycle ergometer for 30 minutes at a resistance of their own choosing. Blood samples were taken from the patients at rest before the pedaling. During exercise and after the exercise, blood samples were analyzed to calculate the amount of many different types of white blood cells. Now, we know the white blood cells are little Pac-Men that attack invaders, fungus, bacteria, viruses, but also they gobble up cancer cells.