Increased amounts of body fat seriously impede performance by being an extra weight burden to the body, interfering with its cooling process and straining the circulatory system. Cardiorespiratory fitness, also known as cardiopulmonary or aerobic fitness, is a good measure of the heart s ability to pump oxygen-rich blood to the body. The person with a health heart, that can pump great volumes of blood with each beat, will have a high level of cardiorespiratory fitness. This is particularly important to individuals who must sustain intense physical effort over long periods, such as required in fire fighting. The metabolic requirements, added burden of protective equipment, and heat stress encountered during fire fighting mandate a higher than average level of aerobic fitness.
Flexibility is defined as the range of possible movement in a joint or group of joints.
Flexibility is included in total fitness assessment because of the widespread problems of low back pain and joint soreness. Back injuries follow heart disease as the second-leading cause of premature retirement among firefighters. Muscular strength is the maximum amount of force that can be exerted by a muscle. Muscular endurance is the ability of a muscle to exert a force over a period of time. Strength and endurance are related, and an increase in one component generally results in improvement in the other.