Related Terms

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

Background

• 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.

Safety

• General: A qualified healthcare provider should be consulted before beginning any new exercise program.

• Like all workout routines, weight training should begin with a warm-up session and end with a cool-down segment that includes stretching exercises.

• Use a spotter when lifting heavy weights.

• If dizziness, pain, nausea, shortness of breath or chest pain occurs stop the exercise and contact a qualified healthcare professional before resuming the exercise routine.

• After completing a weight-training workout, wait 24-48 hours before lifting with the same muscles.

• Isometric: Isometric exercises are generally considered to be safe because the intensity may be adjusted quickly and precisely. These exercises are very fast and should not produce any discomfort. Consult a qualified healthcare professional in patients with a history of heart problems, because isometric exercises drastically reduce the blood flow to the muscle. In turn, blood pressure rises dramatically, and the amount of blood that is able to flow back to the heart reduces. Blood pressure will likely return to a normal level after an exercise is complete; however, this may be dangerous for individuals with high blood pressure or heart disease. Maintaining proper breathing during exercises may reduce the risk for increased blood pressure.

• Isotonic: While generally safe, isotonic exercise can make the muscles sore due to the stress the muscles experience while they lengthen. In addition, the muscles do not equally benefit from this type of exercise. Instead, the muscles that benefit the most are located at the weakest point of action.

• Isokinetic: Isokinetic exercises are generally safe. Since the machines used measure the user's resistance, the danger of lifting more weight than the amount that can be safely handled is eliminated. These exercises increase strength in all muscles evenly, and it is the quickest way to increase muscle strength.

Author Information

• This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Bibliography

Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

1. Bodybuilding for you. www.bodybuildingforyou.com

2. Komi PV, Viitasalo JT, Rauramaa R, et al. Effect of isometric strength training of mechanical, electrical, and metabolic aspects of muscle function.European Journal of Applied Physiology and Occupational Physiology. 1978 Dec 15;40(1):45-55 View Abstract

3. Mayo Clinic. www.mayoclinic.com

4. Sports Fitness Advisor. www.sport-fitness-advisor.com