Muscular strength is the highest amount of effort exerted by the muscles of the body in order to overcome the most resistance in a single effort. A large part of muscle strength is endurance, which is the muscles' ability to repeat the contraction for a longer period of time before it becomes exhausted.
Muscular strength is an aspect of physical fitness that is typically gauged with the maximum amount of weight that a given muscle can move for one repetition. Muscular strength is increased by performing progressive resistance training over time to improve the endurance of the muscle. Increased muscle strength can only be achieved by working the muscle beyond its normal operation in order to break the muscle tissue down in preparation for it to rebuild. As the muscle tires, small tears occur within the muscle fibers. As these tears heal, the muscle becomes stronger. This can be achieved by increasing the number of repetitions, the amount of weight and by shortening times between strength training sessions. Building muscle strength takes time. People looking to put on muscle should never push to lift more weight than the muscle is ready for as injury may likely occur.
The initial benefit of increasing muscle strength is that it improves performance and physical fitness. Other benefits include improved joint health, cardiovascular endurance, flexibility, increased bone density, and a leaner physique with lower body fat, among many others.