Physical fitness can be categorised into cardiorespiratory fitness, muscular fitness and flexibility.
Cardiorespiratory fitness is related to the ability to perform large muscle, dynamic, moderate-to-high intensity exercise for prolonged periods. Performance of such exercise depends on the functional state of the respiratory, cardiovascular and skeletal muscle systems.
Cardiorespiratory (CR) fitness is considered health-related because
- low levels of CR fitness have been associated with a markedly increased risk of premature death from all causes and specifically from cardiovascular disease;
- increases in CR fitness are associated with a reduction in death from all causes; and
- high levels of CR fitness are associated with higher levels of habitual physical activity, which in turn are associated with many health benefits. The assessment of CR fitness is an important part of a primary or secondary prevention program.
Muscular fitness comprises muscular strength and muscular endurance. They are health-related fitness components that may improve or maintain the following:
- bone mass, which is related to osteoporosis;
- glucose tolerance, which is related to type 2 diabetes;
- musculotendinous integrity, which is elated to a lower risk of injury, including low-back pain;
- the ability to carry out the activities of daily living, which is related to self-esteem;
- the FFM (Fat Free Mass) and resting metabolic rate, which are related to weight management. Fat Free Mass comprises muscle, bone, tissue, water, and all other fat free mass in the body.
Muscular strength refers to the ability of the muscle to exert force. Muscular endurance is the muscle’s ability to continue to perform for successive exertions or many repetitions.
Flexibility is the ability to move a joint through its complete range of motion (ROM). It is important in athletic performance and in the ability to carry out the activities of daily living (ADL). Consequently, maintaining flexibility of all joints facilitates movement; in contrast, when an activity moves the structures of a joint beyond a joint’s shortened range of motion, tissue damage can occur.