This myth can be dangerous for people with two distinctly different goals: For those who want to gain muscle and bulk up, following this principle can lead to a frustrating lack of progress, and for those who are trying to avoid bulking up, this false belief causes them to waste their time in the gym almost entirely.
As a trainer, I have often heard (mostly from women, but not always) “I don’t want to look like a body builder,” or “I don’t want to bulk up.” After a remark like that, it usually takes a lot of convincing on my part to make that person pick up a weight heavy enough to do them any good at all. There is one universal fact about building muscle mass: it takes a lot of hard work. Some people are genetically predisposed to put on muscle more quickly than others (lucky people!), but most of us have to spend hours every week following a carefully-designed weight lifting regimen just to pack on a few pounds of lean muscle. This becomes more true every year beyond the age of 30 – learn more about this here. It’s also more true for women than it is for men. Women simply don’t have the hormone profile necessary to “look like a body builder” without an insane amount of work (and often hormone or steroid supplements, too).
Also, that theory that lifting a light weight for a ton of repetitions will “tone” your muscles – it’s just false. Lifting a light weight lots of times is largely ineffective for building size or strength unless combined with other lifting protocols. And that elusive muscle “tone” you’re after actually results from a combination of muscle growth and fat loss. So if you want shapely arms or thighs or six-pack abs, you need to grow some muscle, but more importantly, you need to lose fat. So put down the dumbbell that weighs less than a Kleenex box, pick up a heavier weight, and stop eating chocolate cake and drinking frozen margaritas.
Now consider the clients (usually men, but not always) who want to pack on five or ten pounds of muscle and “get ripped.” These people like to walk over to the dumbbell rack and pick up the heaviest weight they can lift, and then proceed to use every muscle in their body to jerk the weight through a rough approximation of six or eight ugly repetitions. There are many things wrong with this. 1: No one is impressed. Your form is horrible and it looks like you are going to hurt yourself. 2: You are going to hurt yourself. 3: This is completely ineffective because you are using poor form, recruiting help from muscle groups other than the one you’re targeting and using momentum to lift the weight. 4: Even if you were using good form, lifting a weight that heavy builds muscle strength but not necessarily size. 5: You won’t get “ripped” until and unless you lose fat, see comments above, re: cake and margaritas.
Here are the facts, for men and women of all sizes, with any range of goals:
1: Lifting a weight heavy enough so that you can only perform 8 – 12 repetitions with perfect form will build both strength and size. The more sets you do, the more size you will gain (however, anything over 5 sets is largely a waste of time). So, for those looking to gain strength and little size (for that desirable muscle tone), you would do well to perform one or two exercises in two or three sets of 8 – 12 repetitions for each muscle group.
2: Working to fatigue or failure, varying the rest time between sets and varying the speed of your repetitions can also help build muscle size. By working to fatigue or failure, you force a given muscle group to use the maximum number of muscle fibers available. By increasing the weight lifted, you generate more contractile force. However, since the sweet spot for muscle growth is 8 – 12 repetitions per set, using a weight too heavy to allow at least 8 repetitions is counter-productive. The only way to effectively get in more repetitions then, is by doing more sets (3 – 5 is recommended). Varying the speed of your repetitions can also produce greater contractile force: Fast contractions require a great amount of force over a short period of time, whereas very slow repetitions cause the muscle fibers to work longer.
3: Of course there is an exception to the rule! For those new to weight lifting, those who haven’t exercised in more than 6 months and those over the age of 65, starting with a lighter weight and performing 15 – 20 repetitions is safer than using a heavier weight. Once you’ve learned the proper technique and form and gained some strength, then you can graduate to heavier weights and fewer repetitions.
4: For those who want to build super strength without regard for size, pile on the weight! Note that you need to have a good base level of strength, so unless you’ve already been strength training for several months, disregard this paragraph! Lifting heavy, in the range of 1 – 6 repetitions per set for 3 – 5 sets, is the best way to build muscle strength. Be aware, however, that the risk of injury is much higher in this range, and your form must be perfect!
5: The great news is that once you’ve built a base level of strength and lean muscle mass, you only need to complete one or two sets of 8 – 12 reps for each muscle group two or three times per week in order to keep what you’ve got.
I hope this clears up the myth and gives you some direction for your next weight workout. Remember, less can be more sometimes, but perfect form is always mandatory!