17 Sep 2007
Various methods of muscular contractions have been used to improve muscular strength and endurance. Here are a few methods with explanations and benefits.
Static[Isometric] Training- Isometrics involve muscular contractions performed against fixed, immovable resistance. The muscle develops tension, but does not change length. Static exercises are widely used in rehabilitation programs. Isometric training can be used effectively to counteract strength loss and muscle atrophy, especially in cases in which the limb is temporarily immobilized. This method of training would be compared to flexing one's bicep or pushing against a wall and holding the contraction for 6-10 seconds. A major disadvantage of static training is that the strength gains are specific to the angle of the joint used during the training or contraction. Therefore, to increase strength throughout the range of motion, the exercise needs to be performed at a number of different joint angles.
Isokinetic Training- An isokinetic contraction is one in which maximal tension is developed throughout the full range of joint motion. Increases in strength, power and muscular endurance are acquired by mechanically controlling the speed of the movement with with special isokinetic equipment.The availability of this type of equipment is either limited and not available to many.
Dynamic [Isotonic] Training- Dynamic (isotonic) weight-training involves both eccentric and concentric contractions of a muscle group performed against a constant or variable of resistance, (e.g. free weights, Universal, Nautilus, Kaiser, etc.) During a concentric contraction the muscle will shorten as tension is developed (e.g. curling a weight with the biceps). Just the opposite occurs with the eccentric contraction. The muscle lengthens as it develops tension (e.g. setting the weight back down with the biceps). Dynamic training is the most familiar kind of contraction since it is the kind used in all lifting activities. There are three important concepts used to describe and classify dynamic weight-training programs -- repetition, set and repetition maximum.