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. Some studies support the theory that increasing levels of muscular fitness correlate with decreasing incidence of musculoskeletal injuries. The Physical Fitness Assessment Program is a tool used to help individual fire fighters judge their own level of conditioning, but is only one of many factors to consider when looking at fire fighter health and safety. The goal is too help them stay fit, perform at peak efficiency, survive the rigors and stress of a career in fire fighting, and retire healthy.