Junk volume, a term you've probably heard of before but aren't quite sure what it refers to. It definitely sounds like something you'd want to avoid, but what is it exactly? Junk volume is essentially training volume that is not stimulative enough to make you stronger or bigger, or at least not as stimulative as it could be. In this article, we'll explain the different types of junk volume and how to avoid it so that you don't waste your time in the gym and can be sure that your training is effective.
In my article [Understanding Volume & Fatigue] I explain training volume in detail, but it is commonly defined in two major ways. The first is what is referred to as "volume load", which is essentially Sets x Reps x Weight. With this definition, 3 sets of 10 with 100 lbs would equate to 3,000 lbs of volume load.
The second method defines volume by the total amount of "hard sets" that are performed. A "hard set" is a set that is within 4 repetitions or closer to failure. So 3 sets of 10 with 100 lbs would simply count as 3 sets of volume, provided those sets are taken near failure.
For the context of this article we will define volume in terms of hard sets, because total hard sets is more closely correlated to training stimulus. The more hard sets you perform, the stronger the training stimulus, regardless of volume load performed.
Junk volume comes in a few different forms. There can be junk sets, junk reps and even junk exercises. I'll list each below with details on how they commonly come about and what you can do to avoid them.
Remember how I mentioned that a "hard set" is a set that is taken within a certain proximity to failure? Well, a junk set is a set that does not get close enough to failure. The proximity to failure that is generally recommended is 4 reps from failure or closer. A muscle needs to be pushed close to it's limits in order for an adaptive response to take place and that muscle to become stronger and bigger.
If you're capable of picking up a 20 lb dumbbell and curling it 20 times, but you stop curling it at 12 repetitions just because it burns and becomes uncomfortable, your biceps will have no reason to grow and strengthen. Many people are training like this and have no idea that what they're doing is essentially "junk volume" and many of the sets they're performing are not contributing to muscle growth or strength.
Junk reps are very common with people who are "ego lifting", which is lifting a weight that is too heavy to execute with proper form, so they use momentum to get the weight up. This can also occur when someone takes a set near failure and then attempts to get even more reps than their targeted muscles are actually capable of by using momentum to get the weight up or performing "half reps", which is essentially moving the weight only halfway through it's range of motion because the weight being used is simply too heavy.
This is a problem because these types of reps either do not stimulate the targeted muscle at all or in the case of half reps, generate much more overall fatigue than it does additional stimulus.
Choosing the right exercises is very important and can be very individualistic. Just because one exercise works great for someone else does not mean that it will work for you. One of the most important things to consider when choosing exercises is whether or not it stimulates the muscles that you want it to adequately. Just because an exercise is supposed to target a certain muscle doesn't mean that it will for you, at least to a good enough degree to be considered a good exercise for you. For example, if the bench press hits your triceps and shoulders hard, but you barely feel anything in your chest, then it may be sub-optimal to use it as a major chest exercise and you may be better off with a dip variation.
Unless you have a good reason to perform certain movements, you should avoid exercises that require too much momentum, have very short ranges of motion (though partial ROM has benefits for strength development) or have a bad SFR (Stimulus to Fatigue Ratio) ratio. SFR refers to the ratio of stimulus to fatigue that an exercise generates. You wan to select exercises that really stimulate the targeted muscles while generating the least amount of overall fatigue. So you should avoid exercises that cause discomfort and pain.
Now that we know what junk volume is, we'll want to figure out ways to avoid falling into the trap of inadvertently doing junk volume. There are a few ways that we can make sure that every set we do in the gym is providing an adequate training stimulus. Below, I'll list a few things we can do to avoid performing junk volume.
When performing your sets, make sure that every rep uses proper form. When your form begins to break down, stop the set. When we mention the concept of leaving only 4 reps left in you or less, we are referring to reps with good form. Form begins to break down mostly due to local muscle fatigue, meaning the muscles you are targeting have been adequately stimulated. Performing any more reps past this point will not provide additional benefits to hypertrophy and can only lead to reduced recovery due to the added fatigue.
Since we know that junk volume can result from not training close enough to failure, we need a method to judge the intensity of each set that we perform. Two common ways of doing this is by either using the RIR scale or the RPE scale. These two concepts are very similar and attempt to achieve the same goal, which is judging the intensity of a set. Below, we'll briefly describe each one.
RIR stands for "Reps in Reserve" and refers to how many reps you have left in you when you stop a set. If you stop a set at 8 repetitions when you could have gotten 10 repetitions, then this would be an RIR of 2. The lower the RIR, the more intense the set.
RPE stands for "Rate of Perceived Exertion" and refers to how difficult a set feels on a scale from 1-10. Comparing RPE to RIR is pretty straightforward. An RPE of 8 means that the set you performed was an 8/10 in difficulty and can be compared to an RIR of 2, because a set with a difficulty of 8/10 will typically mean you could have done roughly 2 more reps.
Because a set must be taken within 4 repetitions of failure or closer, your working sets should have a minimum intensity of RIR 4/RPE 6.
When new to the RIR/RPE scales, it's common to have the wrong estimations. I talk about this in my article [Training to failure can assist in maintaining proper reps in reserve]. When you think you're at an RPE of 8, you might actually be at an RPE of 6 or 7 and vice versa. Each individual has different tolerance levels for being placed under stress, so estimations can vary in accuracy. To alleviate this problem, you should occasionally train to failure on a given exercise with a given load to see how many reps you can actually achieve. This will allow you to get a true estimate of how many reps it should take to hit a given RIR/RPE range.
If you've been performing 3 sets of 10 with 180 lbs on the bench press and you've been calling it an RIR of 2, but when testing yourself and going to failure with 180 lbs you achieve 15 reps, then you know your true RIR has been 5 all along.
By advanced training techniques, I'm referring to things like super sets, giant sets, drop sets and the like. While these have their places in training, their usage is only effective in very specific cases, such as attempting to save time in the gym when you're strapped for time. Performing straight sets will be more effective 90% of the time, especially for beginners and intermediates.
Straight sets not only win out in productivity 9 times out of 10, but they make it MUCH easier to make sure you're not performing junk volume. When doing super sets or drop sets, you can tire out more quickly, making it harder to accurately judge your RIR/RPE due to overall fatigue. This leads us to our next tip.
Systemic fatigue refers to overall fatigue on the body, while local fatigue refers to the fatigue of a specific muscle or muscle groups. If you perform a few sets of heavy squats, not only will there be a lot of local fatigue in the legs, but your overall systemic fatigue will rise as well. As your workouts progress, systemic fatigue will accumulate and you'll begin to feel more and more burned out.
It's important to not mistake systemic fatigue for local muscle fatigue. What I mean by this is that when you're training a muscle in the latter parts of a workout, make sure you aren't stopping your sets early due to systemic fatigue, but stopping the set when the muscle itself is fatigued. If you're performing a set of barbell curls at the end of a workout, push until the bicep itself is fatigued and having difficulties contracting, not when you feel tired and out of breath from all the other work you've done.