The power to arrest someone who refuses to undergo treatment for a communicable disease lies with: a local health officer.
A local health officer is an individual who works with a local health department (a government agency). A local health officer is responsible for the enforcement of all public health laws, and regulations. He is also responsible for controlling, organizing, and administering all duties and operations of the health department, inclusive of the operation of laboratories, clinics, and health centers.
As you increase exercise and muscle activity, your heart rates increases. That is one feedback mechanism. Your heart delivers oxygen and nutrients to your muscle and other parts of the body quicker.