Resistance Training Part 3
I finished up last month with an important take-home message: Choosing the amount of weight you lift (light or heavy) when performing resistance training for appearance-related purposes is not a function of the specific look you are trying to achieve (e.g., “bulked” or “toned”), but simply a matter of getting the job done properly. However, the amount of muscle you’ll end up developing does depend on your genetic potential for muscle growth and also how far you progress your program once changes begin to take place. This means that if you don’t want an excessive amount of muscle, you should only expose your muscles to a stimulus in excess of that to which they are accustomed up to the point at which they have developed to your liking. Once this has been achieved, you would simply continue to present that same stimulus on a regular basis, which would cause them to be maintained at that level. On the other hand, if you lessened the stimulus significantly or stopped lifting weights completely, they would shrink away (not turn to fat; that’s a myth) and if you upped the ante, they would continue to develop, at least to a point dictated by your genetic blueprint.
Okay, with this in mind, we can now tackle the million dollar question: Exactly how much weight do we have to lift in order to make our muscles respond? In other words, does the aforementioned “stimulus in excess of that to which they are accustomed” have to be associated with a heavy weight? Well, heavy is a relative term, so in order to definitively answer this question, we must first establish an objective method for quantifying the amount of weight we lift. One that is commonly used involves description in relation to the most weight that can be lifted with proper form for a specific number of repetitions. This is called the “repetition-maximum” method or RM for short.
The most common repetition-maximum test is for determination of the 1RM, which is the most weight that a person can lift for one strict repetition. This test is typically used to assess strength changes over time; for example, after three months compared to upon initiation of a resistance training program. However, completing a rep with the most weight you can lift one time is daunting and potentially injurious, so it’s important to realize that the results of tests that determine any RM up to at least 10 can be used to predict the 1RM and, therefore, also reliably track strength changes. But the important thing to understand is that no matter what RM you are referring to, it must be the most weight you can lift for the prescribed number of repetitions, so if you can lift more weight for the same number of reps and/or perform more reps with the same amount of weight, it would not be your true RM for that specific number of repetitions.
To put weight determination via RM quantification into perspective, consider performing dumbbell bench presses to work the muscles of your chest and triceps. For this example, assume you arbitrarily choose a pair of dumbbells and perform a set of presses at a specific cadence; for example, a movement speed that allows you to press the weight completely up in two seconds and lower it back to the starting position in three. If the weight you choose allows you to do 10 repetitions at this pace, but not 11, it would be your 10RM. However, if you complete 10 reps and then decide to stop even though you could have continued simply because 10 is a round number and you heard 10-rep sets were best, you would not have been lifting your 10RM weight, even though you used the weight to perform a 10-repetition set. In this case, you might have been using your 15RM weight and voluntarily terminating the set at 10.
Armed with this understanding, we can now consider important questions regarding how heavy we must lift to achieve our objective in the weight room (i.e., to provide a stimulus to our muscles that is in excess of that to which they are accustomed). For example, do we have to use our 6RM weight or will a lighter weight (for example, a 15RM) suffice? And furthermore, in either case, must we continue our set until we cannot complete another repetition (i.e., to the actual repetition maximum; e.g., repetitions 6 and 15 with the 6RM and 15RM weights, respectively) or can we stop prior to this point? I recently read an article by Dr. Ralph Carpinelli in the Journal of Exercise Science and Fitness that provides information that is helpful for answering these questions. In the world of strength training, Carpinelli has earned his reputation by recognizing what has been proven by scientific investigation and, specifically, how this information is often misrepresented or ignored by influential authors and governing bodies that set the standards in the field. This article explaining misapplication of the size principle of motor unit recruitment (an oft challenged, but yet to be refuted long-standing tenet of neurophysiology) is no exception!
This article was originally published in New Living Magazine, which can be accessed on-line at www.newliving.com.
