It's commonly accepted that lifting heavy weights for low reps leads to muscle gains, whereas lifting lighter weights for high reps promotes fat loss. Commercial propaganda offers the same guidelines, and many novice lifters follow them. Although this might be thought of as a "safe" approach, athletes who primarily want to build muscle should also consider the following points.
When it comes to building muscle—that is, increasing its size and density—you must balance two factors. First, the volume of exercise needs to be on the high side. This refers to how many sets of work you do, per exercise, per workout. The more volume in a workout, the easier it is to put on muscle. The second factor is intensity. Many people attribute a workout's intensity to things like rest intervals, heart rate and level of exertion. In weightlifting, intensity refers to the percentage of the lifter's one-rep max (learn how to determine your one-rep max). To have an effect on muscle building, intensity must be above a certain level.
Several research studies support the conclusion that exercising with these two factors in mind, using multi-joint movements like the Squat, Bench Press and Leg Press, stimulate the release of testosterone and HGH, key ingredients for muscle growth. Even when using moderate intensity, the key factor is the lengthening of the muscle through exertion.
Thus, the best way to make muscles grow is to find the balance between volume and intensity that allows for several challenging reps. I recommend performing five or more sets at 70 percent of your max. Training systems like German Volume Training and 8x8 training are also great options.
Photo: U.S. Air Force