The phrase “relatively close to failure” has been a constant throughout my posts so far. Not only is it extremely important that you take your sets close to failure, the number of sets you take close to failure in a week for a target muscle may be the main driver behind the progress you do see.
Relatively close to failure
As discussed previously, you don’t have to do to failure, just close to failure on every set. The muscular tension you experience when you do a set that is “easy” is negligible when it comes to results. You may as well have not done any work at all since that set minimally stimulated hypertrophy. You don’t want to waste time and energy in the gym without seeing results. You want to make sure that every time you commit to lifting, you get everything that you can out of that commitment.
So how do you measure “relatively close to failure?” You are relatively close to failure if you are within 2 or fewer reps away from failure. The number of reps you do in a set do not matter, as long as the set takes your target muscle close to failure. A set of 10 is as good as a set of 20 as long as the last rep on either set is at least 2 reps away from technical failure. Often times this is referred to as “reps in reserve.” If you can do a max of 10 reps with a given weight, you should be able to do 3 sets of 8 reps with that weight. Each set has 2 reps in reserve (10-2=8), otherwise denoted as “RIR.”
An alternate way to think about it is as a “perceived rate of exertion” or “PRE.” On a scale of 1 to 10, with 1 being very easy and 10 being extremely hard, how hard was the set? A set with 2 reps in reserve would equal to a set that’s rated an 8 on the PRE scale. You want each set you do to be at that 2 RIR or 8 PRE level, if not at 0 RIR or 10 PRE. You want each set to feel hard and you want to make sure that you lift hard in order to maximally stimulate hypertrophy.
Why not to failure?
Training to failure is often employed by many amateur and professional weightlifters, both those who are training for strength and those training for hypertrophy. There are two big problems with training to failure; it risks injury and it accumulates systemic fatigue.
Injuries will set you back more than losing motivation and binging on junk food. An injury will put you out of commission for potentially months, may require medical intervention, and could linger with you for the rest of your life. You want to maximize your gains while minimizing the risk of injury, so training to failure on every set for every workout is not a smart idea. Pushing yourself to the limit is good, but you should make sure you’re staying safe while doing so.
Additionally, failure training will make you downright exhausted. Systemic fatigue - the toll on your body overall - will build up much faster and will take a longer time to recover from if you train to failure every time. You don’t want to have to skip a day because you haven’t been able to recover from the last time you lifted because, as I will talk more about further below, that could actually cost you more gains that you would get from that one extremely hard to-failure session. Balance is key in this equation. You want to push yourself close to failure so that you stimulate hypertrophy without pushing so far that you discover negative externalities.
Perhaps most importantly, studies have repeatedly shown that training within a couple reps shy of failure yields nearly as much hypertrophic stimulus as training to all out failure. If that’s true, why would you risk injury and make yourself unnecessarily tired or sore just to achieve a marginally better stimulus? You could get great results by training close to failure but not to failure on every set without having to worry about added negatives. This doesn’t mean that you shouldn’t ever train to failure. It may be wise to take the last set on a movement to failure just to make sure you’ve exhausted the muscle fibers in your target muscle. You should also know where your actual failure point is to ensure that you aren’t accidentally training more than 2 reps away, so testing yourself periodically and finding your new failure point is a good idea.
Weekly sets
If reps don’t matter very much, sets matter a lot. Not only should each set be taken to failure, but you should be aiming for at least 10 - 12 sets per muscle per week. Think about the units in which you’re counting your exercises in sets taken close to failure rather than reps. You can do any number of reps that take you close to failure on a set, and that set counts as 1. If you do 3 sets of that exercise that day and then another exercise the same day that also targets the same muscle for 3 sets, that’s 6 sets for that muscle for the week so far. On another day later that week you do the same two exercises for the same 6 sets for the day, bringing you up to 12 sets total for the muscle for the whole week.
This is called volume. While you can calculate your volume by multiplying weight x reps x sets (trying to increase the volume over time would constitute progressive overload), the most important element of the equation is your set number. The reps and weights you chose are only relevant to the individual set, and as long as you are selecting weight and rep ranges that take your set close to failure, it’s all that matters. What ends up making the biggest difference is the number of hard sets you do on a weekly basis, each set maximally stimulating your muscles. What matters is how many times you take your muscles close to failure in a week.
Increasing your number of sets for an exercise from 3 to 4 drastically changes your weekly volume. Taking the same example from above, if you add just one more set for one movement, you go from 12 sets for that muscle per week to 14 sets. If you add one set to both movements, you are now doing 16 sets. What if instead of adding sets to those two exercises you added a new exercise that also worked the same target muscle for 3 sets twice a week? Now you’re doing 18 sets. What if you kept the two exercises for 3 sets but added a third day? Now you’re doing 6 sets, 6 sets, and 6 sets again for 18 sets for the week.
Each additional set is one more time you’ve forced your muscles to go close to failure, stimulating your body to build more muscle.
Junk volume
There is a ceiling to how many sets you can do, both in a day and in a week. The typical term for sets that don’t do all that much to help you grow is "junk volume.” If you’ve already worked one muscle with 3 different exercises, each done for 3 set with each set done with 2 or fewer RIR, you’ve already maximally stimulated that muscle. Any additional set you do on top of that will certainly tire you out, but it’s unlikely to generate much more hypertrophic stimulus.
Let’s take the chest, for example. You first did 3 hard sets of incline bench press. Then you moved on to 3 hard sets of flat bench press. Finally, you finished it off with 3 hard sets of chest fly. Would it really be helpful to add in another 3 sets of something like dips? At this point, your chest should already be tired from 9 hard sets of work. The muscle fibers of your pectoralis have been stimulated through 3 different exercises, all of which challenged them in different ways from different angles. This is the point of diminishing returns because you’ve already sent your body a signal that said “this muscle has been worked to 100% of its potential,” it’s not possible to send your body a signal that’s 110%, assuming all the sets were legitimately hard sets.
When looking at your set numbers over the course of the week, it becomes a bit more complex. A recent study made waves after showing that 52 sets had a higher hypertrophic response than any lower set number. It seems that the number of sets you perform in a week and the subsequent hypertrophic stimulus can be mapped in a somewhat linear fashion, where the hypertrophic stimulus increases with each added weekly rep. That would mean that you should do as many sets as you possibly can to maximally stimulate hypertrophy, right?
The problem here is that it’s not feasible to do 52 sets for multiple muscle groups per week for multiple weeks. The study mentioned only focused on one muscle’s growth, so the participants could devote time and energy to doing 52 sets in a week. If you intend to grow more than one muscle, you will have to do a lower number of sets. You have to pick and chose which muscles you work in a day and in a week. Trying to fit 52 sets in a week of any exercise is hard for a person who has other commitments in life outside of lifting, so shoving as many sets into a week is just not realistic. On top of that, the systemic fatigue you would experience from than many sets in a week would require longer rest times, which is harder to do if you’re working out 6 days per week trying to squeeze a few more sets in.
Instead, figure out what muscles are your priorities and select standard exercises that work them. You can select multiple exercises that work the same muscle, which helps hit the muscle with more sets. Focus on doing at least 10 - 12 hard sets per muscle per week, with each set being taken at least within 2 RIR of failure. Most importantly, try to increase the number of reps you do in a set or the weight you’re lifting for each exercises on a weekly basis to ensure that you’re progressively overloading the muscle.