Despite the stereotype of a weight lifter - muscle-bound, hefting and grunting, big but weak - weight training can be used by everyone, not just those interested in becoming body builders.
Paired with regular aerobic exercise, weight training increases your strength and muscle endurance as well as your overall feeling of fitness in ways that no other single exercise can. Bicycling develops one set of muscles, basketball another, but weight training works out a whole range of muscles in a very short amount of time.
Specific weight-training routines can be used to help you develop particular muscle groups that will improve your performance in your chosen sport.
True enough, nothing improves your tennis games as much as playing tennis: specificity is the iron rule of modern sports training. Nonetheless, upper-body training will give you an extra edge in tennis, and developing your leg muscles will improve your swimming kick.
Basic Principles of Weight Training
-The basic principle of any sort of muscle development is that of overload: contracting a muscle group against added resistance. The way a muscle grows is by splitting, longitudinally, under the strain placed on it, and "healing" after the workout by adding protein. Over a period of time, the overload placed on the muscles is increased a step at a time, and so the muscles continue to develop.
-The three modes of exercise for developing muscles are isometric, isotonic, and isokinetic. In isometric exercises, you contract a muscle group without moving the joint to which the muscles are attached - for instance, pushing steadily against an immovable wall. These exercises build muscle, but the gain occurs mainly at the angle at which the muscle is exercises.
-Isotonic exercises, by contrast, contract a muscle through a range of motion - as you can do with movable weights. The virtue of isotonic exercises is that they build muscle through this full range of isometric exercises. Isokinetic exercises also consist of contracting a muscle through a range of movement. But isokinetic exercises, which are performed on machines, use equipment designed to apply maximum stress to the muscles through the whole range of movement.
