In any exercise program, 3 fundamental variables are always present: intensity (how hard it is), duration (how long the workout takes), and frequency (how often you work out). Each of these variables must be properly manipulated to maximize progress. The cornerstone of any program designed to increase muscle growth is intensity. Intensity provides the stimulus for muscle growth; if the intensity of the workout is too low, no muscle growth will occur, no matter how long your workouts are or how often you work out. To prove this point in your own mind, consider the following example:
Let’s say you can perform ten repetitions of barbell curls with 100 pounds with proper form, and no matter how hard you try you cannot complete an 11th rep. The 10th repetition is the last possible rep; therefore, we would call this a set of 10 reps to failure. Now for your question: in that set of 10 reps to failure, which rep would you say was the most PRODUCTIVE in terms of increasing your muscular size and strength-the first rep (the easiest) or the last rep (the hardest)?
Obviously, the last, hardest rep is the most productive rep of that set-the one and only rep that will provide the stimulus for growth. Now here is the key issue: what if you didn’t do that rep? Many people go into the gym with a preconceived set-and-rep scheme in mind, such as 3 sets of 8, 5 sets of 5, etc. In our example, if the trainee stopped their set of curls arbitrarily at 8 reps, THEY WOULD NEVER DO THE ONE AND ONLY MOST PRODUCTIVE REPETITION, no matter how many sets were performed. 100 sets of a sub-maximal effort will never equal the growth stimulus of one set with a maximum effort.
It should be clear from this discussion that intensity-the percentage of maximum momentary effort being exerted-is the key factor in your workouts. With that in mind, understand that there are many ways to vary your workouts and still end up with a maximum effort. Techniques such as partner-assisted reps, negatives, super sets, time under tension, etc. etc. are all viable options for achieving that all-important point of muscular failure discussed earlier. It is wise to vary your intensity techniques to provide variety and prevent physiological plateaus and/or mental staleness. This is where a personal trainer adept at such techniques is invaluable, because intensity must be accompanied by the proper duration-the harder your workout is, the shorter it must be. How you decide to utilize intensity variables is up to you and your trainer, but make no mistake-anything less than a maximal effort on every set (other than warm-ups) will result in less than maximal results. Arrive at the gym committed to going all-out, and the results will be commensurate. Go for it!