There is one fundamental part of the repetition that is just as important—if not more so—than the lifting portion itself. For some reason, however, it’s often times minimized, or worse, completely ignored; diluting the effect of every exercise, rep by rep.
Before we jump in and discuss the, potentially, most important part of every repetition, let’s first layout the anatomy of a rep.
The Anatomy of a Rep
There are three components to a repetition in each exercise:
Concentric: The concentric contraction refers to the portion of the lift where we’re pushing (or pulling) against resistance; shortening the muscle under load.
During a biceps curl, for example, the concentric portion of the lift occurs when you’re curling the weight up.
Eccentric: The eccentric contraction—or negative—refers to the portion of the lift where we’re lowering the weight; lengthening the muscle under load.
During a biceps curl, the negative refers to the part of the lift where you’re lowering the weight back down.
Isometric: The isometric contraction happens at both the starting and ending point of a lift when the weight is motionless
Sticking to the biceps curl example, the isometric contraction occurs at the top of the curl when your biceps are flexed, and at the bottom of the lift when your arm is fully extended.
In a race to becoming the most critical important part of a rep, the isometric contraction is far behind while the eccentric and concentric battle it out for 1st place.
I won’t go as far as to say that one is, in fact, more important than the other, but I will say this: if you’re not taking advantage of the negative, you’re not going to maximize muscle growth.
This isn’t to state the obvious: we should control the weight through the entire rep; that should go without saying.
I’d like to introduce something less intuitive: negative training.
A Case for Heavy Negatives
It’s no secret that we are much stronger on the eccentric portion of the lift than we are on the concentric—we can handle more weight on the way down than we can actually lift up. The reason is simple: we're going with the resistance (and not against it), so it requires less energy.
Now let’s talk about how, in practice, negative training could make for bigger gains. Say, for example, you’re stuck bench pressing 225 pounds for 5 reps—for one reason or another, you can’t squeeze out the 6th. Sure, maybe you can’t lift the weight up for another repetition, but could you lower it back down? Absolutely. So who’s making greater gains—the guy who stops at 5 reps, or the one who has his buddy assisting with every rep after the 5th and then letting him handle the negative on his own? I think the answer is obvious.
Here’s the problem, though: this style of training isn’t practical because it requires not just a consistent gym partner, but a competent one. That said, however, I have a solution.
Enter Cheat Reps
Using body English or momentum to aid with a lift is, in most bodybuilding circles, frowned upon; and with good reason. Often referred to as Ego Lifting, cheat reps have been demonized by form Nazis all across the interwebz who claim they’re a one way ticket to Snap City. I disagree.
Here’s the thing: not all cheat reps are created equal. For example, you can’t compare the meathead who’s bench pressing with his ass 6 inches off the bench, with the advanced lifter who’s swaying slightly to get the barbell back up to the starting position on a biceps curl. One is extremely dangerous and can cause serious injury, while the other is purposeful and far from threatening.
Take a look at the following images: Example A. depicts a potentially dangerous cheat curl (no offence to Arnold); Example B. demonstrates the use of purposeful—and non-hazardous—body English.
I think it’s safe to say that not all cheat reps are created equal. That said, properly—and safely—executed cheap reps can very well make the biggest impact on your arm growth.
It's no secret that, at a certain point, it's no longer as simple as curling more weight than you did last week . And because progressive overload is the main driver of muscle growth, we to need to handle more load. But we’re at a point where we just can’t add any more weight to the bar, so what do we do? We cheat!
Not only is using momentum going to increase the workload by aiding with additional reps, but despite how little work the target muscle is doing on the concentric, it’s still doing all of the work on the negative.
A Case for Cheating
Cheat reps don’t have to be something you implement at the end of an exercise in order to get a bit more out of the set, however. In fact, I’d argue that, with some exercises, cheating throughout the entire set is going to put massive amounts of size on your arms.
Let’s take a barbell curl for example. Say, for the sake of argument, your max barbell curl with strict form is 135 pounds—if you used a bit of body English, you could squeeze out 5 reps, safely. Although you wouldn’t be maximizing the amount of stress placed on the biceps during the concentric portion of the lift, you’re still handling an insane amount of weight during the negative; more weight than you could ever dream of with a strict curl.
This is not to say that cheating is better; that we should use momentum for all of our lifts in order to emphasize the negative. It’s simply a useful tool that, if implemented correctly, can take your arm development to another level.