RedWine
05-19-2007, 07:23 AM
Weight training is a common type of strength training for developing the strength and size of skeletal muscles. It uses the force of gravity (in the form of weighted bars, dumbbells or weight stacks) to oppose the force generated by muscle through concentric or eccentric contraction. Weight training uses a variety of specialized equipment to target specific muscle groups and types of movement.
Weight training differs from bodybuilding, weightlifting, powerlifting and strongman, which are sports rather than forms of exercise. Weight training, however, is often part of the athlete's training regimen.
Strength training is an inclusive term for all types of exercise devoted towards increasing muscular strength and size (as opposed to muscular endurance, associated with aerobic exercise, or flexibility, associated with stretching exercise like yoga or pilates, though endurance and flexibility can improve as a byproduct of training).
Weight training is one type of strength training, but the most common and is seen by all but specialists as synonymous with strength training. The difference between weight training and other types of strength training is how the opposition to muscular contraction is generated. Resistance training uses elastic or hydraulic (water) forces to oppose muscular contraction and isometric exercise uses structural or intramuscular forces (e.g. doorways or the body's own muscles).
Weight training can be one of the safest forms of exercise, especially when the movements are slow, controlled, and carefully defined. However, as with any form of exercise, improper execution can result in injury. When the exercise becomes difficult towards the end of a set, there is a temptation to cheat, i.e. to use poor form to recruit other muscle groups to assist the effort. This may shift the effort to weaker muscles that cannot handle the weight. For example, the squat and the deadlift are used to exercise the largest muscles in the body—the leg and buttock muscles—so they require substantial weight. Beginners are tempted to round their back while performing these exercises. This causes the weaker lower back muscles to support much of the weight, which can result in serious lower back injuries. To avoid such problems, weight training exercises must be performed correctly. Hence the saying: "train, don't strain".
An exercise should be halted if marked or sudden pain is felt, to prevent further injury. However, not all discomfort indicates injury. Weight training exercises are brief but very intense, and many people are unaccustomed to this level of effort. The expression "no pain, no gain" refers to working through the discomfort expected from such vigorous effort, rather than to willfully ignore extreme pain, which may indicate serious soft tissue injuries.
Discomfort can arise from other factors. Individuals who perform large numbers of repetitions, sets and exercises for each muscle group may experience lactic acid build-up in their muscles. This is experienced as a burning sensation in the muscle, but it is perfectly harmless. These individuals may also experience a swelling sensation in their muscles from increased blood flow (the "pump"), which is also harmless. True muscle fatigue is experienced as a marked and uncontrollable loss of strength in a muscle, arising from the nervous system (motor unit) rather than from the muscle fibers themselves. Extreme neural fatigue can be experienced as temporary muscle failure. Some weight training programs actively seek temporary muscle failure; evidence to support this type of training is mixed at best. Irrespective of their program, however, most athletes engaged in high-intensity weight training will experience muscle failure from time to time.
Beginners are advised to build up slowly to a weight training programme. Untrained individuals may have some muscles that are comparatively stronger than others. An injury can result if, in a particular exercise, the primary muscle is stronger than its stabilising muscles. Building up slowly allows muscles time to develop appropriate strengths relative to each other. This can also help to minimise delayed onset muscle soreness. A sudden start to an intense programme can cause significant muscular soreness. Unexercised muscles contain cross-linkages that are torn during intense exercise.
The Cross Trainer exercise machine can be used to warm up muscles in both the upper and lower body.Weight trainers commonly spend 5 to 20 minutes warming up their muscles with aerobic exercise before starting a workout. They also stretch muscles after they have been exercised. The exercises are performed at a steady pace, taking at least two to four seconds to lift and lower the weight, to avoid jerks that can damage muscles and joints.
Exercises where a barbell is held above the body, such as the squat or the bench press, are normally performed inside a squat cage, which can catch the bar, or in the presence of one or more spotters, who can safely re-rack the barbell at the end of the set if the weight trainer is unable to do so.
Anyone beginning an intensive physical training programme is typically advised to consult a physician, because of possible undetected heart or other conditions for which such activity is contraindicated.
There have been mixed reviews regarding the use of weightlifting belts and other devices, such as lifting straps. Critics claim that they allow the lifter to use more weight than they should. In addition, the stabiliser muscles in the lower back and gripping muscles in the forearms receive less benefit from the exercises.
These terms combine the prefix "iso" (meaning "same") with "tonic" (strength) and "plio" (more) with "metric" (distance). In "isotonic" exercises the force applied to the muscle does not change (while the length of the muscle decreases or increases) while in "plyometric" exercises the length of the muscle stretches and contracts rapidly to increases the power output of a muscle.
Weight training is primarily an isotonic form of exercise, as the force produced by the muscle to push or pull weighted objects should not change (though in practice the force produced does decrease as muscles fatigue). Any object can be used for weight training, but dumbbells, barbells and other specialised equipment are normally used because they can be adjusted to specific weights and are easily gripped. Many exercises are not strictly isotonic because the force on the muscle varies as the joint moves through its range of motion. Movements can become easier or harder depending on the angle of muscular force relative to gravity - in example, a standard biceps curl becomes easier as the hand approaches the shoulder as more of the load is taken by the structure of the elbow. Certain machines such as the Nautilus involve special adaptations to keep resistance constant irrespective of the joint angle.
Plyometric exercises exploits the stretch-shortening cycle of muscles to enhance the myotatic (stretch) reflex. This involves rapid alternation of lengthening and shortening of muscle fibers against a resistance. The resistance involved is often a weighted object such as a medicine ball, but can also be the body itself as in jumping exercises. Plyometrics is used to develop explosive speed, and focuses on maximal power instead of maximal strength by compressing the force of muscular contraction into as short a period as possible, and may be used to improve the effectiveness of a boxer's punch, or to increase the vertical jumping ability of a basketball player.
Weight training differs from bodybuilding, weightlifting, powerlifting and strongman, which are sports rather than forms of exercise. Weight training, however, is often part of the athlete's training regimen.
Strength training is an inclusive term for all types of exercise devoted towards increasing muscular strength and size (as opposed to muscular endurance, associated with aerobic exercise, or flexibility, associated with stretching exercise like yoga or pilates, though endurance and flexibility can improve as a byproduct of training).
Weight training is one type of strength training, but the most common and is seen by all but specialists as synonymous with strength training. The difference between weight training and other types of strength training is how the opposition to muscular contraction is generated. Resistance training uses elastic or hydraulic (water) forces to oppose muscular contraction and isometric exercise uses structural or intramuscular forces (e.g. doorways or the body's own muscles).
Weight training can be one of the safest forms of exercise, especially when the movements are slow, controlled, and carefully defined. However, as with any form of exercise, improper execution can result in injury. When the exercise becomes difficult towards the end of a set, there is a temptation to cheat, i.e. to use poor form to recruit other muscle groups to assist the effort. This may shift the effort to weaker muscles that cannot handle the weight. For example, the squat and the deadlift are used to exercise the largest muscles in the body—the leg and buttock muscles—so they require substantial weight. Beginners are tempted to round their back while performing these exercises. This causes the weaker lower back muscles to support much of the weight, which can result in serious lower back injuries. To avoid such problems, weight training exercises must be performed correctly. Hence the saying: "train, don't strain".
An exercise should be halted if marked or sudden pain is felt, to prevent further injury. However, not all discomfort indicates injury. Weight training exercises are brief but very intense, and many people are unaccustomed to this level of effort. The expression "no pain, no gain" refers to working through the discomfort expected from such vigorous effort, rather than to willfully ignore extreme pain, which may indicate serious soft tissue injuries.
Discomfort can arise from other factors. Individuals who perform large numbers of repetitions, sets and exercises for each muscle group may experience lactic acid build-up in their muscles. This is experienced as a burning sensation in the muscle, but it is perfectly harmless. These individuals may also experience a swelling sensation in their muscles from increased blood flow (the "pump"), which is also harmless. True muscle fatigue is experienced as a marked and uncontrollable loss of strength in a muscle, arising from the nervous system (motor unit) rather than from the muscle fibers themselves. Extreme neural fatigue can be experienced as temporary muscle failure. Some weight training programs actively seek temporary muscle failure; evidence to support this type of training is mixed at best. Irrespective of their program, however, most athletes engaged in high-intensity weight training will experience muscle failure from time to time.
Beginners are advised to build up slowly to a weight training programme. Untrained individuals may have some muscles that are comparatively stronger than others. An injury can result if, in a particular exercise, the primary muscle is stronger than its stabilising muscles. Building up slowly allows muscles time to develop appropriate strengths relative to each other. This can also help to minimise delayed onset muscle soreness. A sudden start to an intense programme can cause significant muscular soreness. Unexercised muscles contain cross-linkages that are torn during intense exercise.
The Cross Trainer exercise machine can be used to warm up muscles in both the upper and lower body.Weight trainers commonly spend 5 to 20 minutes warming up their muscles with aerobic exercise before starting a workout. They also stretch muscles after they have been exercised. The exercises are performed at a steady pace, taking at least two to four seconds to lift and lower the weight, to avoid jerks that can damage muscles and joints.
Exercises where a barbell is held above the body, such as the squat or the bench press, are normally performed inside a squat cage, which can catch the bar, or in the presence of one or more spotters, who can safely re-rack the barbell at the end of the set if the weight trainer is unable to do so.
Anyone beginning an intensive physical training programme is typically advised to consult a physician, because of possible undetected heart or other conditions for which such activity is contraindicated.
There have been mixed reviews regarding the use of weightlifting belts and other devices, such as lifting straps. Critics claim that they allow the lifter to use more weight than they should. In addition, the stabiliser muscles in the lower back and gripping muscles in the forearms receive less benefit from the exercises.
These terms combine the prefix "iso" (meaning "same") with "tonic" (strength) and "plio" (more) with "metric" (distance). In "isotonic" exercises the force applied to the muscle does not change (while the length of the muscle decreases or increases) while in "plyometric" exercises the length of the muscle stretches and contracts rapidly to increases the power output of a muscle.
Weight training is primarily an isotonic form of exercise, as the force produced by the muscle to push or pull weighted objects should not change (though in practice the force produced does decrease as muscles fatigue). Any object can be used for weight training, but dumbbells, barbells and other specialised equipment are normally used because they can be adjusted to specific weights and are easily gripped. Many exercises are not strictly isotonic because the force on the muscle varies as the joint moves through its range of motion. Movements can become easier or harder depending on the angle of muscular force relative to gravity - in example, a standard biceps curl becomes easier as the hand approaches the shoulder as more of the load is taken by the structure of the elbow. Certain machines such as the Nautilus involve special adaptations to keep resistance constant irrespective of the joint angle.
Plyometric exercises exploits the stretch-shortening cycle of muscles to enhance the myotatic (stretch) reflex. This involves rapid alternation of lengthening and shortening of muscle fibers against a resistance. The resistance involved is often a weighted object such as a medicine ball, but can also be the body itself as in jumping exercises. Plyometrics is used to develop explosive speed, and focuses on maximal power instead of maximal strength by compressing the force of muscular contraction into as short a period as possible, and may be used to improve the effectiveness of a boxer's punch, or to increase the vertical jumping ability of a basketball player.