Have a rest when you are tired. Drink water when you are thirsty. Go to see a doctor when you are sick. These are good habits formed by people over the years. But there is someone in health center advises a positive or active to keep yourself in good health. People's sweatful endurance is limited. When tired exceed the maximum, health would get damaged. It is better to have a rest when you are not tired. Water is one of the six major nutrients essential to human body. Water plays a irreplaceable role in mainteining life activity. People should drink more water more often. It is a healthy action for the old to drink water on their own. In recent years, check your body actively becomes a new fashion for health care. Although health care get more and more favor from people, we should still master definite methods to preserve our health so as to build a strong body.