Fitness may mean the state of being physically active on a regular basis to maintain good physical condition. A general state of good health, usually as a result of exercise and nutrition with balanced diet. Fitness is a form of physique training, related to bodybuilding. Physical fitness is generally achieved through exercise. These days, physical fitness is considered a measure of the body's ability to function efficiently and effectively in work and in leisure activities, to be healthy, to resist diseases, develop immunity and to meet emergency situations. Many sources also cite mental and emotional health as an important part of overall fitness of human health. If you are physically fit, you are free from illness, and able to function efficiently and effectively, to enjoy leisure, and to cope with emergencies. Health-related components of physical fitness include body composition, cardiovascular fitness, flexibility, muscular endurance, and muscle strength.