Exercising the different muscular groups with the correct equipment is absolutely essential for muscle building. The equipment should have variable resistance settings, specifically free-weight. Heavy weights should be used. However the weight should still be appropriate by giving you the ability to do only eight reps. Low reps and heavy weights stimulates muscle growth substantially because of the strain on the muscle- and nerve system. Technique is just as important as the right equipment. You will just waste your time if you work out for hours on the right equipment but employ the wrong techniques. By employing wrong techniques in combination with the heavy weights, you are at risk of sustaining serious and long-term injuries.