The overall objectives of a boxing strength and training program are similar to those found in most contact sports, emphasizing physical fitness and endurance. Boxing is atypical in that it places equal emphasis on the ability of the athlete to deliver and to absorb powerful physical blows in competition, without significant protective equipment.
Boxing has been variously described as the "sweet science" and as "show business with blood." A successful boxer will be required to commit to a focused and demanding physical training program that will incorporate a number of overarching principles, including: intensity; physical strength; injury reduction; training regimen variety; and mental training, especially with respect to the boxer's ability to deal with pain.
It is the nature of boxing that the athlete will compete in a series of two- to three-minute segments, or rounds, interspersed with one-minute rest intervals. The length and the number of rounds will vary depending on the age of the competitor and the level of competition. There are often shorter periods of extreme activity, as in a flurry of punches exchanged or delivered. The punching mechanism, the defensive blocking mechanism, and the boxer's movements within the ring require a smooth synchronization of arm, core, and leg functions. Leg strength is particularly important in the stability of a boxer, as well as assisting in the generation of power in a punch. Boxers adopt a stance that is a posture similar to the crouched position of athletes in other sports, such as a fielder in baseball; this position is generally referred to as the athletic position. In boxing, this position is known as a fighting stance. This stable stance permits the boxer to better react to the movements of the opponent, as well as provide an optimum physical platform from which to deliver a punch.
The short intervals within which the boxer competes place high demands on the body's anaerobic energy system; the efficient recovery of the boxer between rounds will depend on the aerobic capacity of the boxer, as aerobic fitness is a determining factor in how quickly the heart rate returns to resting level. The entire body must be trained for a boxer to successfully compete; particular focus is placed on the neck, shoulders, bicep, triceps, wrists and hands, and the abdominal, gluteal, and leg muscles.
As boxing competitions are organized on the basis of weight divisions—athletes compete against an opponent of similar size—boxing strength training is centered on relative strength, which is the strength of the boxer in relation to his weight as opposed to absolute strength. The act of delivering a punch requires the development of ballistic strength, the term used to describe the starting strength available to a boxer at the commencement of a punch.
The manner in which boxing blows are generated by the arm muscles is also a factor in how a boxing strength and training regimen should be developed. The delivery of a punch involves rapidly accelerating and decelerating the fist, and to a lesser degree, the attached musculoskeletal structure.
The various training goals of a boxer can be achieved through employing all or some of the following techniques: running, plyometrics; and arm (muscle), leg (muscle), and core strength development.
Running, the legendary road work (or indoor training machine work) of the boxer, will develop the aerobic capacity of the athlete. Jumping rope and skipping are exercises that allow the boxer to both build aerobic capacity and develop footwork and agility. Plyometric exercises develop ballistic strength. The plyometric exercises used by boxers focus on the explosive capability of the upper body and arm muscles; they may include the rapid performance of push-ups or chin-ups, as well as rapid repeated throws with a medicine ball.
A regimen designed for arm, and particularly triceps, development is enhanced with push-ups, or similar exercises that have the effect of extending the triceps through their full range. Sessions with the boxing heavy bag, the large punching bag weighted to provide extra resistance to a punch, place additional, muscle-building stress on the triceps. Boxers also train with a speed bag, a smaller, lighter object that helps them develop reflexes and build muscular endurance. Leg strength can be developed, in part, through aerobic running. Explosive leg strength will be developed through leg press exercises and plyometric training. Finally, core strength development, that of the muscle structure of the abdomen, pelvis, and gluteal muscles (buttocks), will provide both increased protection of vital internal organs, as well as contributing to the stability of the body. Core strength exercises include sit-ups, abdominal crunches, and rowing machine workouts.
It is essential to a successful boxing strength and training program that the athlete incorporate appropriate rest intervals into the schedule and pay strict attention to diet and nutrition. The demands of high-level strength training, coupled with the forces applied to the body through boxing competition, compel many boxers to maintain a training log, where all training, rest, competition, and nutritional matters are noted.