The most widely accepted definition of good health is that of the World Health Organization Constitution. It states that "health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity" (World Health Organization, 1946). In more recent years, this statement has been amplified to include the ability to lead a "socially and economically productive life". The WHO definition is not without criticism, mainly that it is too broad. Some argue that health cannot be defined as a state at all, but must be seen as a process of continuous adjustment to the changing demands of living and of the changing meanings we give to life. It is a dynamic concept. the WHO definition is therefore considered by many as an idealistic goal rather than a realistic proposition. Using the WHO definition, 70-95% of people are classified as unhealthy. In spite of the above limitations, the concept of health as defined by WHO is broad and positive in its implications. It sets out a high standard for positive health. It represents the overall goal that nations should strive to reach.
The most solid aspects of wellness that fit firmly in the realm of medicine are the environmental health, nutrition, disease prevention, and public health matters that can be investigated and assist in measuring well-being.
In its most general meaning, physical fitness is a general state of good physical health. A physically handicapped person's body may be physically fit (healthy), though its ability is likely to be less than optimum.
Physical fitness is usually a result of regular physical activity and proper nutrition.
Help you control your weight:
Along with diet, exercise plays an important role in controlling your weight and preventing obesity. To maintain your weight, the calories you eat and drink must equal the energy you burn. To lose weight, you must use more calories than you eat and drink.
Reduce your risk of heart diseases:
Exercise strengthens your heart and improves your circulation. The increased blood flow raises the oxygen levels in your body. This helps lower your risk of heart diseases such as high cholesterol, coronary artery disease, and heart attack. Regular exercise can also lower your blood pressure and triglyceride levels.
Help your body manage blood sugar and insulin levels:
Exercise can lower your blood sugar level and help your insulin work better. This can cut down your risk for metabolic syndrome and type 2 diabetes. And if you already have one of those diseases, exercise can help you to manage it.
Help you quit smoking:
Exercise may make it easier to quit smoking by reducing your cravings and withdrawal symptoms. It can also help limit the weight you might gain when you stop smoking.
Improve your mental health and mood:
During exercise, your body releases chemicals that can improve your mood and make you feel more relaxed. This can help you deal with stress and reduce your risk of depression. Help keep your thinking, learning, and judgment skills sharp as you age. Exercise stimulates your body to release proteins and other chemicals that improve the structure and function of your brain.
Strengthen your bones and muscles:
Regular exercise can help kids and teens build strong bones. Later in life, it can also slow the loss of bone density that comes with age. Doing muscle-strengthening activities can help you increase or maintain your muscle mass and strength. Reduce your risk of some cancers, including colon, breast , uterine, and lung cancer.
Reduce your risk of falls:
For older adults, research shows that doing balance and muscle-strengthening activities in addition to moderate-intensity aerobic activity can help reduce your risk of falling.
Improve your sleep:
Exercise can help you to fall asleep faster and stay asleep longer.
Improve your sexual health:
Regular exercise may lower the risk of erectile dysfunction (ED) in men. For those who already have ED, exercise may help improve their sexual function. In women, exercise may increase sexual arousal.
Increase your chances of living longer:
Studies show that physical activity can reduce your risk of dying early from the leading causes of death, like heart disease and some cancers.