Generally, the potential value of an exercise can be judged effectively on four basic factors.  (1) It should engage the muscles through a full range of motion, based on all the major muscles involved rather than just a single body part. (2) It should involve as many muscles as possible; hence compound movements are superior to isolation exercises. (3) Where possible it should provide resistance at the point of full contraction. (4) It should involve the largest muscle groups of the body or the greatest individual mass possible.

Including all four characteristics, in every exercise performed, is almost impossible.  Occasionally, only one of the four factors will be present.  However, whenever a possibility, you should aim for exercises that include should all four factors. Doing this is by far the one of the best ways to build muscle fast.

The barbell squat involves a large mass of muscle; the leg muscles.  It is a compound exercise and therefore involves many other smaller muscles simultaneously.  However, it doesn’t provide resistance when the legs are locked in the fully contracted position.  Even in spite of this, the barbell squat is the single  most effective muscle building exercise available.

Although most exercises lack one or more factors, it is still possible to design an effective  routine which consists of only a few compound exercises.  A well designed routine will produce outstanding muscle gains in almost everyone who uses it.  As a you begin to understand the principles here, you must remember that too many exercises will ‘screw’ your recovery ability.  Avoid this at all costs.  If you ignore this fact, increases in muscle mass will be almost impossible.