There’s a reason it’s tough to squat 405 pounds during a powerlifting meet, yet any Joe Schmo at your local health club makes it look like light work. No, it’s not because the average gym goer is massively stronger than guys who train specifically for strength; it’s because while the powerlifter is forced to squat all the way down to parallel—or below—the meathead is squatting down only a quarter of the way.
The reason partial reps make it easier to load up the bar is simple: First—and more obvious—with a partial repetition, the bar travels through a shorter range of motion. Second—and less commonly discussed—you’re training the muscle from its strongest position.
Take a look at the following illustration:
The point I am trying to make, however, has little to do with training a muscle through a full range of motion—although that is what we’re, technically, discussing here. But rather, it has to do with strengthening the muscle from its weakest position—the point where the target muscle is fully lengthened.
To illustrate the point, take a look at the previous image: it’s going to be much easier to take a 50 pound dumbbell from 50 to 100 degrees than it would to take the same weight from 0 to 50—because your biceps are at their weakest point at 0 degrees.
The benefits of training the arms through a full range of motion are twofold: (1) training a muscle through a full range activates muscles along their entire length and (2) stretching a muscle under tension is a strong stimulus for muscle growth; creating a longer and thicker muscle.
This is not to say that there isn’t a time or place for partial reps or cheat curls; however, if you’re looking to maximize your efforts in the gym, true full range of motion is a hard and fast principle that you can never go wrong with.
Now that we understand the importance of training a muscle from its weakest position, let’s talk about how you can ensure you’re, in fact, at the weakest point of the lift.
The simple answer is this: a muscle is fully lengthened—or in its weakest position—when the antagonist muscle is flexed.
The Fear of Full Extension
If you’re performing these movements correctly, then you’ll quickly realize that they require you to lock out or get a full extension; something that most meatheads would encourage you to avoid. This, however, can be a huge mistake.
First, understand this: there is a big difference between extension (safe) and hyperextension (unsafe).
The function of the biceps and triceps are flexion and extension of the arms—particularly at the elbow joint. So why wouldn’t we train our arms using their intended function?
Hyperextension, however, is, by definition, an excessive joint movement in which the angle formed by the bones of a particular joint is opened, or straightened, beyond its normal, healthy, ROM.
And although many may say that training a muscle through a full range of motion, particularly when we’re locking out on a joint, is unsafe, it couldn’t be further from the truth. In fact, the opposite is true.
If you fail to strengthen the muscle through its full range of motion, you’re also failing to strengthen the connective tissue surrounding that joint; a recipe for disaster in the future.
Leave Your Ego at the Door
I must warn you, as much as you want to lift heavier in the gym, this strategy will require you to leave your ego at the door. When I began to implement this technique, I was forced to use less than half of the weight I was used to lifting.
Though quite simple, this small tweak to your training will make a huge impact. Ignore it, and you’ll be leaving a ton of growth on the table. Implement it, however, and your arms will grow like never before.