In Defense of Set Increases Within the Hypertrophy Mesocycle

by Dr. Mike Israetel, Chief Sport Scientist / Jared Feather, MS, IPE & NFF PRO / Dr. James Hoffmann / Anshuman Radhakrishnan | Jun 30, 2020


In the evidence-based community, there has been some contention of late about the practice of adding sets within a hypertrophy mesocycle. In opposition to adding load, reps, and sets within a mesocycle such as we at RP and James Krieger advocate, some have pushed forward a defense of the more established practice of adding only load and reps within a mesocycle, and only adding sets between mesocycles. This contention is excellent, as it sparks discussion and moves the community closer toward the truth. To that end, here is our input on that discussion, in defense of using weekly (within-mesocycle) set additions during muscle growth training mesocycles.

"This article is a response to several critiques and critics of the volume progression concept. Notably, the works of Eric Helms and Brian Minor on the subject, and their upcoming critique of our SCJ article on this topic, as well as elements of Eric's MASS article and YouTube video on similar subjects."

1.  Most mesocycles should start at MEV

Starting each meso at the minimum effective volume (MEV) for hypertrophy has big upsides. First, starting with lower volumes can reduce the volume jump from the preceding deload week, reducing the chance of injury from rapid escalations in volume. Second, training at MEV means you make gains in muscle, but at the smallest costs of both injury risk and fatigue accumulation. Those easy gains are small and won’t last if you keep training that easily, but starting at anything much harder than MEV just misses the lowest cost gains for no good reason. Near-MEV gains are “low cost” in the sense that you get a robust stimulus for a very tiny fatigue contribution. Eventually, the stimulus must be higher and thus so must the fatigue, but when low volumes can stimulate robust gains, doing volumes much higher pays a higher fatigue cost for seemingly no good reason. Lastly, starting at MEV gives you an extra week or two to practice the exercises in your mesocycle, building technique and strength momentum for just that much longer, and making it more likely that the whole rest of the mesocycle will be both longer (due to increased exercise efficiency and lower initial fatigue) and more productive (due to the higher stimulus to fatigue ratio (SFR) of the exercises).

2.  You don’t want to stay at MEV, as MAV is the eventual target

You don’t want to STAY at MEV unless you literally want minimal gains, so MEV is best only as an intro into effective volumes, and going up to something that at least tries to approximate your maximal adaptive volume (MAV), which causes the best gains. By analogy, just because meals are best started with appetizers, doesn’t mean all you have is appetizer for the whole meal. There’s a place for the main course at the very least. Research has shown that the majority of beginner-intermediate lifters see SOME (at least MEV) gains with 3 sets per muscle group per session, and rarely is this an insufficient volume from which to grow at all. But research also shows that optimal gains are seen with programs that average around 8 sets per muscle group per session. Thus, if we think there is value to starting at MEV (or at least with fewer than average sets per session), we MUST add some sets during the mesocycle to get to the MAV volumes that cause the best average gains, lest our MEV and MAV are very close together, which can happen for the more advanced and we will address later.

3.  Work capacity gains are rapid and can allow easy expansion into higher volumes

Work capacity goes up very quickly week to week, and there doesn’t seem to be a good argument against using it to do more volume. In most studies, within 3-8 sets per session, more volume leads to more gains, so if you start around 3 and your work capacity allows more, why not add more slowly and safely in a gradual manner? There may be reasons for not adding, but none of them seem very compelling or obviously the right choice. For example, some have stated that the studies testing the effects of differing volumes on growth didn’t progress their volumes for each subject, but compared across groups, and thus using them to infer progression within subjects is untenable. However, if we’re not willing to infer that such a progression is tenable from these studies, we’d also have to infer all sorts of other between-subjects research is invalid for the sorts of applications it’s regularly used for. For example, we know from various studies that exogenous testosterone grows more muscle in a dose-dependent manner, but almost all of those are between-subjects studies. We also know that doing more cardio leads to more weight loss, and eating less leads to more weight loss as well, and most of those studies are between-subject designs. But, we’d hardly tell someone not to progress upward in their exogenous testosterone administration if they wanted more muscle, or to not add in more cardio or not eat less food if they wanted to keep their absolute weight loss to the same rates.  At the end of the day, if you have the energy to do another set of squats and you’ve only been doing 4 sets of squats per session, doing a 5th set might very well be a good idea, lest you cannot recover from it, which brings us to the next point. 

4.  Recovery ability gains are rapid and can allow easy expansion into higher volumes

Recovery ability improves rather quickly from session to session via many mechanisms, notably the repeated bout effect. Especially after the desensitization to volume of a deload, very low volumes can make you very sore and stiff, and can delay your return to usual performance (the textbook definition of recovery). But after just the next session, that same given low volume is likely to lead to much less damage and recovery is attained much faster. A few sessions later, you might hardly be getting sore, if at all, and you can perform at or above baseline the next day. This dynamic presents even if you don’t alter exercise selection and rep ranges between mesocycles, but when you do, it’s even more pronounced. If you do lunges for the first time in a while, only one set can leave you obliterated for days, but mere weeks later, 6 sets barely get you sore. If your recovery ability goes up along with your work capacity over the course of days and weeks after you begin your meso, why not slowly do more and get more growth? 

It’s tough to admit that you’re recovering way ahead of schedule, have more than enough work capacity to do more, but won’t increase your set volume at all despite this reality. At some level, perhaps you’re not challenging yourself as much as you could be and missing out on potential gains. 

5.  Estimates at meso-average MAV are much higher than MEV, and much higher than what is prudent to start with, even MEV aside

We already know two things:

A.) The average volume for best per-session gains is around 8 sets per muscle group.

B.) Starting at 8 sets after a deload week can cause a huge rise in acute:chronic workload ratio, and enough damage to slow or stop growth in the first week(s). The lack of growth due to damage in early phases of programs that break right into moderate-high volumes has been well documented.

Knowing those two things, why would we NOT start with a volume lower than what causes massive, needless damage and injury risk (point B above) and work up over the meso to bring our average volume to around its MAV (point A)? The alternatives are to either start at a suboptimal volume (less than about 8) and stay there, getting fewer gains, or start at 8 sets and stay there, risking excessive damage and increases in injury likelihood. 

6.  Stimulus proxies desensitize to volume within weeks, not months

If you run a mesocycle for enough weeks with no volume increases at all, you might eventually be in a place where pumps and soreness (not just DOMS, but acute and immediate evidence of disruption) are minimal. It’s possible that people can make their best gains without any notable disruption (minimal or no pump, minimal or no post-training weakness, no soreness of any kind), but it seems unlikely. In most studies on beginners, pumps, weakness, and soreness are nearly ubiquitous, and because most studies find that higher volumes promote more growth, (within the 3-8 sets per session range), the subjects growing the most are probably also the ones getting the biggest pumps, most post-training weakness, and a higher degree of soreness. Volumes that are much lower (2-4 sets per session) are excellent for strength enhancements and often don’t produce big pumps, weakness, or soreness. But such volumes are already well known to cause less muscle growth than the higher volumes that do cause more disruption.  Adding to this fact, the pump is almost certainly a noteworthy stimulus proxy in its own right, as it has been directly linked to hypertrophy mechanisms. Thus, if you are getting no pump at all from training after a while, it’s possible that you’re getting less growth than otherwise. 

In other words, if you’re no longer getting pumps or much of any disruption to the target muscle at a given volume and you’re recovering by a long shot, not doing a bit more if you have the work capacity seems curious at least.

If someone is asking you how your training is going, and you inform them that you’re recovering very easily, have plenty of work capacity to do more, and aren’t getting as good of pumps or perturbation to the target muscle as you used to, they might ask you why you haven’t made the training harder, and you might be hard pressed to find a convincing answer. 

7.  It’s very tough to gauge the volume that stimulates best performance gains week to week because of fitness and fatigue dynamics

A good reason why you might not want to increase your volume week to week in a mesocycle is that it becomes difficult to track what volume level improves performance the most. If you alter your volume, you might not be able to see where you’re strongest, and thus keeping volume stable week to week can let you see with which volume you gain the most strength meso to meso, and thus let you choose your best volume after several mesos of experimentation with lower and higher volumes. You definitely need to compare strength improvements meso to meso, because week to week strength improvements are shrouded in the mystery of the fitness-fatigue paradigm. Week to week, both fitness and fatigue rise over the course of any given mesocycle. It’s hard to tell if you’re performing more poorly because fitness is going up more slowly, or if fatigue is going up more quickly. Thus, it’s not very easy to tell which weekly volume promotes the best gains week to week, and only after each meso's deload can you tell how much strength the average weekly volume added over the last meso. This is not an invalid concern, but runs into at least two problems:

1.) You CAN alter weekly volume within a meso, and you'll still get an average per-week volume for the whole meso after the deload, and you can use the strength results from that average to move the average up or down in the next meso. In other words, every week doesn't need to be the same volume for you to observe the relationship between strength and volume and act on it.

2.) More troublingly, the relationship between strength, volume, and hypertrophy is not as straightforward as "do whatever volume increases your strength the most." In multiple studies, higher volume training resulted in the same strength increase as lower volume training, but more hypertrophy. Thus, if you find the volume that causes your best meso-to-meso strength increases, you at least want to see if raising the average meso volume further in future mesos causes the same strength gain. If it does, then you're very likely growing more with the higher volumes but the same strength gains, as the studies suggest. 

So instead of choosing a stable weekly volume for one meso at a time and choosing the volume that most improves strength after multiple trials of different stable volumes, you might be better off both cycling volume within the meso, and then finding the highest of those meso average volumes to use to cause the most muscle growth.

There doesn't seem to be a need to wait to add sets meso to meso. We don’t wait two mesos to autoregulate load or reps. We autoregulate and target RIR for those (hitting the goal of ‘tough’ training every week), so why not autoregulate for set additions too? For example, if we’re really defending the practice of waiting a whole mesocycle to determine which set volume is best, why aren’t we doing that to determine which load is best, which number of reps is best, and which RIR is best? It seems we are treating set additions differently than load and reps, and it’s not clear why. After all, set increases are just “magnitude of stimulus” increases like load, reps, and RIR changes, and if our recovery ability and work capacity make enough room for a whole set to be added, why not do it?

In the end, allowing load, reps, and RIR to change within the meso but categorically leaving volume changes off limits during the meso seems arbitrary. Nearly every problem with letting volume go up during meso can be described for letting RIR go down, and that is a claim almost no one is making!

A related argument is that sets are too large a unit of addition in progression. Adding reps or load is supposedly better, as smaller increments can be used. First, this is not always the case. Adding one rep (from 5 reps to 6 reps) is a higher relative volume increase than adding 1 set from 10 sets to 11 sets. Thus, rep additions are already not categorically more modest than set additions. Second, if we go from 4 to 0 RIR over the course of a meso, we are essentially adding something like 400% “effective reps,” over the meso. Thus, if a 30-50% absolute volume from set additions is too much, then such a massive increase in effective reps might also warrant consideration. Perhaps progressions are best seen in their own domains, and thus what might be a very reasonable progression for volume might be a low progression for reps, a crazy progression for load, and too little of a progression in RIR? Lastly, if the individual is recovering easily and is ready for a higher stimulus, there doesn’t seem to be a good reason to avoid elevating volume, as no objective argument against this decision (something more compelling than “this just seems like too much”) seems viable. 

8.  Increasing volume only when a plateau in rep strength is hit assumes volume must be the problem

If the idea is to increase volume only when a plateau in strength has been hit, how do we know volume increase is what solves the problem? Plateaus could be due to a nutrition or lifestyle issue, and the answer might be to reduce volume or to take an active rest phase. The commonly presented logic is that volume should only be increased if a plateau in results is reached, but again, why don’t we use the same approach with load, reps, or RIR?

9.  Crossing over into the down-side of the U-Shaped curve is not a great concern

There is a very realistic concern that by increasing volume over the mesocycle, you can end up being on the other side of the hypertrophy and volume U-shaped curve, and thus be doing more work and accumulating more fatigue and injury risk for the same gains of doing much less. However, by starting around MEV by the time you get close to the tipping point of the curve, you’ve already accumulated a lot of fatigue. Doing any more training at those volumes and beyond summates even more fatigue, thus very rapidly leading you to your maximum recoverable volume (MRV). Once the MRV is breached, the accumulation phase of training generally ends and the athlete moves into a deload. If you start at meos-average MAV, not only do you present a ton of needless disruption at the front end, but you also risk having enough recovery resources left to train for a considerable time at above the U-shaped tipping point. But, by starting at MEV, training at above the tipping point for much longer than a week or two is probably highly unlikely, especially if your program lowers RIR targets every week or two, as we recommend. 

In other words, there are only so many weeks of training to failure at high volumes that anyone can do without reaching their MRV, so the chances that volume progression gets you and keeps you in this “gray zone” for long is very low. 

10.  Functional Overreaching in hypertrophy has support

If there’s a “gray zone” of volume between MAV and MRV where we get very expensive gains (with regard to fatigue accumulation and injury), perhaps it’s wise to avoid that altogether, and stop all mesocycles just shy of MRV. This might be a good move for beginners whose exercise techniques will break down at near MRV volumes, but for intermediates and advanced lifters, it might not be the obviously correct move. 

It’s not obviously correct because short periods of beyond MRV volumes have been shown recently to cause delayed muscle growth for up to a week after the cessation of such high volume training. Such high volumes are highly risky to perform if you haven’t worked up to them slowly, but if you’ve gone from MEV and are approaching MRV, you’re already primed for them. You can absolutely choose to forgo them and just deload early, but choosing to carefully execute them for a week and grow during your deload week might also be a valid option. And because this option exists, it defends the idea that training is productive all the way from MEV to MRV, even if you don’t choose to exploit that entire range. 

11.  The more advanced you are, the more your MEV-MRV window narrows

As lifters gain more experience, their MEVs escalate, but their MRVs often escalate slower and then stop escalating well before MEVs do. This leads to a narrowing of the MEV-MRV window. For example, beginners might see detectable gains between 2 and 8 sets per session, but someone very advanced might only see detectable gains between 5 and 7 sets per session. That is not an argument against adding sets week to week. It is just an argument for adding fewer sets. In much the same way, you stop getting stronger as fast as you become more advanced. But because you’re adding strength less quickly, we don’t say you shouldn’t be adding any weight or reps over the weeks of a mesocycle, we just say that perhaps you should be adding fewer of them over any given time span.

12.  Volume increase is not the only injury increasing variable

It’s absolutely the case that increasing volume magnifies the injury risk from any training activity, both by exposing you to more time of the same risk of getting hurt (like driving more miles increases your chance of a car accident), and by increasing fatigue and thus even further elevating risk (like driving for more time after you’re really sleepy further increases car accident risk). But increasing the reps in a set, especially between 5 and 10 set reps, increases volume comparably to set additions, and also lowers the RIR, exponentially increasing the fatigue contribution and failure proximity, thus also increasing injury risk. Even more pertinently, load increases expose the connective tissues to higher absolute forces, and higher-load but lower-volume resistance training (Powerlifting and Weightlifting vs. Bodybuilding) is more injurious than higher volume resistance training at lower loads in the empirical literature. And, if only load increases are used to progress, they must be higher than if load and set increases are used in combination, since all of the stimulus increase must then come from load increases, further increasing load-driven injury risk. Thus, if load and rep increases are considered safe, there’s no good reason to think set reasons are any less safe, especially if they are increased in an autoregulated manner based on recovery status. 

As a related aside, using set increases, especially in beginners, might have some advantages on the technique learning and psychological fronts. Only increasing reps and load might lead especially beginners to chase both load and reps, allowing their technique to deteriorate as the sets near failure. By adding sets instead of load and reps, there’s no increase to rep-chase and thus better technique learning might occur, especially given the fact that added submaximal sets offer more technical practice and thus learning enhancement. We do not advocate such set-only progressions for intermediate and advanced lifters, but using set progressions with smaller load and rep progressions in such lifters might temper the “I have to add much more load and reps to each session” attitude and support a less ego-driven and thus emotionally chaotic training process. Adding sets is much more of the psychology of “get the work done” rather than the potential psychology of “hit PRs or else” of only rep and load increases. 

13.  Adding and subtracting volume should be an autoregulated process

We advocate that most hypertrophy mesocycles can begin at around MEV and add sets gently every week IF WARRANTED. The process by which such a decision to add sets is made can involve as many as three inputs: performance recovery, perceptive recovery, and perceptive stimulus proxy.

Performance recovery is when you’re as strong or stronger for reps in your next workout. If you’re consistently improving your performance from workout to workout, or your performance is stable and not declining, then your fitness is improving as fast as your fatigue, and thus you’re free to stay at the volume level you’re at or add some volume. Doing LESS volume than what you can comfortably recover from on a consistent basis might miss out on gains. If you’re doing so much volume that your performance is declining, then you definitely shouldn’t add any volume, and a significant reduction in volume to reduce fatigue is much more prudent.

Perceptive recovery is how sore and stiff you’re getting from workouts and whether or not you can heal on time for the next session. If you’re still sore when you train the same muscle group again, your volume is probably too high and adding more is unwise. If you’re just barely healing on time for your next workouts, you’re probably not doing too much volume, but are unlikely to be doing too little, and keeping volume stable is a good idea. If you’re healing days ahead of your next workouts (or not getting sore at all) and your performance is stable or climbing, then there is a good chance that you can be doing more volume and benefiting, and thus an addition is an option. 

Perceptive stimulus proxy is essentially how much pump and post-exercise weakness in the target muscle you’re experiencing post-workout. If your performance is stable or elevated, if your soreness is recovering ahead of schedule, and if your pumps and post-exercise weakness are starting to be mediocre, then a consideration of adding volume is worthwhile. If you’re getting mondo pumps and falling down the stairs after leg workouts, then adding volume might be either a needless or negative. 

In other words, if you’re recovering easily in both performance and soreness, and your workouts are less than impressive in pump and perturbation of muscle function, adding volume might be the best idea. But if you’re barely hanging in there or your pumps and perturbations are wild, adding volume is at best pointless and at worst risky. If you’re not recovering (soreness then hangs around continuously for weeks, consistent underperformance in workouts, etc.), then a rapid reduction of volume to near-MEV is probably a good idea at least for the local muscle, and perhaps a full-body deload isn’t the worst idea either, especially if multiple muscles are failing to recover at the same time. 

Lastly, the magnitude of set addition must reflect your training reality. If you did 2 sets for chest and you didn’t get sore at all and the workout caused no pump or weakness to note, then it’s probably ok to do 4 sets of chest next time. But if you’re recovering from soreness very early but you’re getting great pumps and your chest is super weak after training with 5 sets, doing 5 or 6 sets next week is a good idea, and there’s at best no need, and at worst a major downside, to doing 7 sets. In fact, in much of our own training, we (being advanced) only move about 2-3 sets per muscle per session TOTAL over the course of the whole 4 week accumulation phase! 

If you’re moving from 2 to 4 to 6 to 8 sets per session on autopilot, you will likely get very good gains. But the risk that you’re doing too much too soon, or, not enough, is not one you need to accept. Autoregulated set additions and subtractions as described above are superior to pre-planned increases and should almost always be preferred to them. 

If you’d like a much more detailed discussion of these concepts and many other volume related topics, please check out How Much Should I Train?