Muscle contraction

Related Terms

Barbells, circuit training, contraction, dumbbells, elastic bands, exercise, muscle contraction, muscular endurance, muscular strength, resistance training, weight lifting, weightlifting, weight training.


Exercise is a planned, structured and repetitive physical activity. Exercise not only conditions the body, but it also improves health, maintains fitness and helps rehabilitate injured parts of the body. Exercise includes cardiovascular activities like running or walking as well as weight training. All workouts should begin with a warm-up routine and end with a cool-down segment that includes stretching exercises. Each of these activities should be done for 3 to 5 minutes. There are three main techniques used for muscle training.
Isometric: Isometric muscle training is the contraction of a muscle against an immovable force. For instance, muscles will flex and hold a stationary position when an individual pushes against a wall. This weight training technique involves no weight and very little equipment. Isometric muscle training allows for the contraction of the muscles but not the shortening or movement of the targeted muscle. Isometric exercise is primarily used in physiotherapy and rehabilitation following an injury. For optimal results isometric training is usually preformed in conjunction with isotonic training.
Isotonic: Isotonic muscle training involves contractions where tension is equal throughout the range of motion. Isotonic exercise strengthens the muscles in the entire range of motion, while improving joint mobility. It involves the contraction and shortening of a muscle to allow movement. Isotonic muscle training is usually done with dumbbells, barbells or elastic resistance bands. (If such equipment is not available, push-ups may be substituted.) This muscle training technique employs eccentric and concentric movements. When the weight is lifted, the movement is referred to as concentric and when the weight is returned back to the starting position, the movement is called an eccentric movement.
Isokinetic: Isokinetic muscle training is a type of contraction where the speed of movement is fixed and resistance varies with the force exerted. In other words, the harder an individual pushes or pulls, the more resistance is felt. It involves muscle contractions that shorten the muscle at a constant speed. This method is mostly used for sports training or rehabilitation following an injury. This form of training usually requires the use of a machine. The user applies force to this machine, and the machine will produce a reading of how much force or resistance was applied.

Theory / Evidence

The benefits of exercise are widespread, both physical and emotional. Clinical trials have shown that strength training of all sorts effectively helps build muscle strength and provides many health benefits. For instance, weight training may prevent osteoporosis, coronary heart disease and diabetes as well as reduce risk of fatigue and depressive symptoms. Exercise also increases joint mobility and endurance. It may delay signs of aging, help with cardiac rehabilitation, muscle rehabilitation (after an injury), general health and endurance.

Author information

This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (


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