Exercise

Main article: Physical exercise

A U.S. Marine emerges from the water upon completing the swimming leg of a triathlon.
Exercise is the performance of movements in order to develop or maintain physical fitness and overall health. It is often directed toward also honing athletic ability or skill. Frequent and regular physical exercise is an important component in the prevention of some of the diseases of affluence such as cancer, heart disease, cardiovascular disease, Type 2 diabetes, obesity and back pain.
Exercises are generally grouped into three types depending on the overall effect they have on the human body:
Flexibility exercises such as stretching improve the range of motion of muscles and joints.
Aerobic exercises such as walking and running focus on increasing cardiovascular endurance and muscle density.
Anaerobic exercises such as weight training or sprinting increase muscle mass and strength.
Physical exercise is considered important for maintaining physical fitness including healthy weight; building and maintaining healthy bones, muscles, and joints; promoting physiological well-being; reducing surgical risks; and strengthening the immune system.
Proper nutrition is just as, if not more, important to health as exercise. When exercising it becomes even more important to have good diet to ensure the body has the correct ratio of macronutrients whilst providing ample micronutrients; this is to aid the body with the recovery process following strenuous exercise. When the body falls short of proper nutrition, it gets into starvation mode developed through evolution and depends onto fat content for survival. Research suggest that the production of thyroid hormones can be negatively affected by repeated bouts of dieting and calorie restriction[5]. Proper rest and recovery is also as important to health as exercise, otherwise the body exists in a permanently injured state and will not improve or adapt adequately to the exercise.
The above two factors can be compromised by psychological compulsions (eating disorders such as exercise bulimia, anorexia, and other bulimias), misinformation, a lack of organization, or a lack of motivation. These all lead to a decreased state of health.
Delayed Onset Muscle Soreness can occur after any exercise, particularly if the body is in an unconditioned state relative to that exercise and the exercise involves repetitive eccentric contractions.

Health maintenance

Main article: Self care
Achieving health and remaining healthy is an active process. Effective strategies for staying healthy and improving one's health include the following elements:

Nutrition
Main article: Nutrition

The updated USDA food pyramid, published in 2005, is a general nutrition guide for recommended food consumption.
Nutrition is the science that studies how what people eat affects their health and performance, such as foods or food components that cause diseases or deteriorate health (such as eating too many calories, which is a major contributing factor to obesity, diabetes, and heart disease). The field of nutrition also studies foods and dietary supplements that improve performance, promote health, and cure or prevent disease, such as eating fibrous foods to reduce the risk of colon cancer, or supplementing with vitamin C to strengthen teeth and gums and to improve the immune system.
Personal health depends partially on the social structure of one’s life. The maintenance of strong social relationships is linked to good health conditions, longevity, productivity, and a positive attitude. This is due to the fact that positive social interaction as viewed by the participant increases many chemical levels in the brain which are linked to personality and intelligence traits. Essentially this means that positive reinforcement from a third party make one more socially adept, in control, and relaxed physically and mentally, all of which are proven to effect the nervous system(UHF).

Sports nutrition
Main article: Sports nutrition
Sports nutrition focuses the link between dietary supplements and athletic performance. One goal of sports nutrition is to maintain glycogen levels and prevent glycogen depletion. Another is to optimize energy levels and muscle tone. An athlete's strategy for winning an event may include a schedule for the entire season of what to eat, when to eat it, and in what precise quantities (before, during, after, and between workouts and events). Participants in endurance sports such as the full-distance triathlon actually eat during their races. Sports nutrition works hand-in-hand with sports medicine.