Physical health is a state of health and well-being, and more specifically, the ability to exercise, work and perform daily activities. Physical health is usually achieved by proper nutrition, moderate vigorous physical exercise and adequate rest.

Before the industrial revolution, fitness was defined as the ability to perform daily activities without over fatigue. However, with the change of automation and lifestyle, physical health is now considered as an indicator of the body's ability to effectively and effectively perform its functions in work and leisure activities, maintain health, resist lack of exercise and cope with emergencies.

Fitness is defined as the quality or state of fitness. Around 1950, perhaps in line with papers from the industrial revolution and the Second World War, the term "adaptability" increased tenfold at home in the West. Modern definition of adaptability describes the ability of human or machine to perform specific functions, or describes the overall definition of human adaptability to various situations. This has led to the interconnection between human fitness and attractiveness, thus mobilizing the global fitness and fitness equipment industry. With regard to specific functions, fitness is attributed to people who have obvious aerobic or anaerobic abilities, i.e. strength or endurance. A comprehensive fitness program can improve a person's health in all aspects compared to exercising only one person (such as exercising only heart / respiratory endurance or exercising only weight).

Comprehensive fitness programs for individuals typically focus on one or more specific skills, as well as age or health-related needs, such as bone health. Many sources also mention that mental, social and emotional health are important components of overall health. This is usually represented by a triangle composed of three points in textbooks, representing physical, emotional and mental health respectively. Physical health can also prevent or treat many chronic health conditions caused by unhealthy lifestyle or aging. Exercise can also help some people sleep better and may reduce some of their emotional disorders.

Continuous research shows that many benefits of exercise are mediated by the function of skeletal muscle as an endocrine organ. In other words, contractile muscles release a variety of substances, called actins, which promote the growth of new tissues, tissue repair and various anti-inflammatory functions, thus reducing the risk of developing various inflammatory diseases.