Achieving health and remaining healthy is an active process. Effective strategies for staying healthy and improving one's health to an optimum level include the following elements:

Nutrition

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.

Between extremes of optimal health and death from starvation or malnutrition, there is an array of disease states that can be caused or alleviated by changes in diet. Deficiencies, excesses and imbalances in diet can produce negative impacts on health, which may lead to diseases such as scurvy, obesity or osteoporosis, as well as psychological and behavioral problems. Moreover, excessive ingestion of elements that have no apparent role in health, (e.g. lead, mercury, PCBs, dioxins), may incur toxic and potentially lethal effects, depending on the dose. The science of nutrition attempts to understand how and why specific dietary aspects influence health.

Sports nutrition

Sports nutrition focuses on how food and dietary supplements affect athletic performance (during events), improvement (from training), and recovery (after events and training). 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.

Physical exercise

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[3]. 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.

Hygiene

Hygiene is the practice of keeping the body clean to prevent infection and illness, and the avoidance of contact with infectious agents. Hygiene practices include bathing, brushing and flossing teeth, washing hands especially before eating, washing food before it is eaten, sterilizing food preparation utensiles and surfaces before and after preparing meals, and many others. See personal hygiene, oral hygiene, and food hygiene.

Health care

Health care is the prevention, treatment, and management of illness and the preservation of mental and physical well being through the services offered by the medical, nursing, and allied health professions. According to the World Health Organisation, health care embraces all the goods and services designed to promote health, including “preventive, curative and palliative interventions, whether directed to individuals or to populations”.[4] The organized provision of such services may constitute a health care system. This can include a specific governmental organization such as the National Health Service in the UK, or a cooperation across the National Health Service and Social Services as in Shared Care.

Natural health

In alternative medicine, natural health is an eclectic self-care system of natural therapies concerned with building and restoring health and wellness via prevention and healthy lifestyles. Natural health includes diet, exercise, chiropractic, naturopathy, herbalism, natural hygiene, homeopathy, massage therapy, relaxation techniques (e.g. Yoga, Tai Chi), accupuncture, sauna, aromatherapy, ayurveda medicine, and Kneipp therapy.

Workplace wellness programs

Workplace wellness programs are recognized by an increasingly large number of companies for their value in improving the health and well-being of their employees, and for increasing morale, loyalty, and productivity. Workplace wellness programs can include things like onsite fitness centers, health presentations, wellness newsletters, access to health coaching, tobacco cessation programs and training related to nutrition, weight and stress management. Other programs may include health risk assessments, health screenings and body mass index monitoring. Mostly overseen or not mentioned is a group of determinants of health which could be called coincidence, hazard, luck or bad luck. These factors are quite important determinants of health but difficult to calculate.