Progressing for Hypertrophy: Strategies for Optimal Muscle Growth

We all know that we have to train hard to get muscle gains. We also know to keep making our best gains we have to train HARDER over time.

The thing is, that’s where the consensus usually stops. What does “harder” mean? Most people will default to “heavier,” and they’re not wrong. But heavier-as-harder, if we’re going to be very honest about it, was simply inherited from the strength training community without a whole lot of thought. Some, but not a ton. In strength training, harder almost always does mean heavier. But in the quest for pure size, there are other ways to make training harder that might impact growth.

Three Ways to Overload

Overload has been defined as pushing a system into the threshold beyond which it is challenged enough to meaningfully adapt. In our case, this means training hard enough to cause muscle growth. That being said, there are at least three ways in which we can measure overload, or rather, three overload thresholds.

The obvious one is for intensity. If a weight is too light, it doesn’t cause muscle growth in anyone but pure beginners. While it’s murky as to what exactly counts as “too light,” research is starting to show that something like 30% 1RM or less is just not getting anywhere near best gains in size. With volume equated, anything heavier seems to cause more growth, but probably just a little more, so long as workload and RIR is similar. Speaking of RIR, that’s our second way to overload.

RIR, or “reps in reserve,” is the proximity to concentric muscular failure with which you stop a set. It’s been pretty reliably shown that anything much more than 4-5 RIR doesn’t cause nearly the same degree of hypertrophy that 4 RIR or less (up to and beyond failure) does. So now we know that if we’re trying to overload for size, we need to train at least at around 30% 1RM and with at least around 4 RIR or so to get good results.

Lastly, is volume. Volume is the amount of training you do, often measured in the number of working sets per week in a program. A volume that is high enough to just get you any detectable growth is your Minimum Effective Volume (MEV) and more volume has been shown to be better up until you reach your Maximum Recoverable Volume (MRV).

An important point to note with all three of these thresholds is that they are thresholds, and not single points on a graph. In other words, there is a bottom end to them and a top end, and everything in between gets you growth. You might be tempted to just shoot for the top of each threshold (the hardest training) to get the best growth, and you’d be right… in part. The problem with the higher rungs of the threshold is that while they probably cause the most growth, they also generate the most fatigue. And fatigue generation has been very well demonstrated to occur exponentially with ascension through the threshold. In other words, while stopping all sets at 4 RIR might cause a good bit less growth than stopping them at 0 RIR, it causes a tiny fraction of the fatigue, even if volume is equated between conditions. So yes, if you have to train once and get as much growth as you can, maxing out each threshold of intensity, RIR, and volume is a great idea. But you’ll have so much fatigue then that you’ll need to take time off of hard training to recover, and you miss out on productive growing time that way. So what if you just avoid the top end and just stay at the safe bottom? Then we are literally engineering our programs to get us minimum results. If we account for fatigue and effectiveness, it starts to look like most of the overload threshold produces a very similar amount of growth. If that’s the case, why not cut the middle and simple train at 60% 1RM, 2RIR, and halfway between MEV and MRV all the time? Why do we need to progress at all?

Reasons to Progress

Can we stay in the middle of all three overload threshold and get good gains for a long time? Absolutely. But they won’t be our best gains for two reasons. In other words, here are the two main reasons we need to progress in our training:

1.) To stay in the overload threshold.

If you don’t progress in your training, it will still grow you for months. But at some point, the magnitude will be so low that you will no longer be in several of the thresholds. For example, if even if you keep RIR 2 the whole time, at some point, your 60% 1RMs will turn into your 29% 1RMs and your volumes will drop below MEV. After all, can you imagine if you still did the same workouts you did 5 years ago? That’s like a warm-up for some of you now! Heck, even keeping RIR 2 gets tough, because at some point, equating total volume means you might just be doing a few sets of RIR 2 per workout and just that alone will get you enough volume to match historical levels.

If you don’t progress for any other reason, you have to progress just enough to stay north of 30% 1RM and MEV. But wait, there’s more!

2.) To chase maximum adaptive responses, not just minimum ones.

If you follow the method above and just progress enough to stay in the overload threshold, you’re staying only at the bottom of it and by definition getting minimum gains. You don’t want minimum gains… you want best gains. So why not just stay in the middle of the threshold and get them there, upping your volume and intensity as-needed to stay in the middle of both ranges and thus keep RIR 2 as well? Well, because what was getting you maximum gains one week will not be enough to get you those gains next week. First because of your increasing fitness but also because of fatigue. It’s important to have a good ratio of stimulus to fatigue, and because fatigue accumulates, that’s easier said than done. If we always train RIR 2, we start our mesocycles with a good ratio, but as fatigue accumulates, our ratio sucks more and more and because we insist on staying at RIR 2, we aren’t really doing anything about it.

As fatigue accumulates and we get closer to what has to be our deload anyway, we might as well tap into the upper end of the RIR spectrum and get those great gains, because our program is going to time itself out anyway due to high fatigue… we might as well grow a lot too. As an example, if it’s your last week of a progression (before deloading) you’re stopping every set at 2 RIR, what would you say to someone that asked “why don’t you go to failure or close this week?” The truth is, you wouldn’t have a good answer.

On the other hand, why start at 2 RIR when we can get good gains at 4 RIR? Injury risk and fatigue accumulation are really low at that relative intensity, and we can build momentum with improved technique on the exercises and a better mind-muscle connection when we finally hit the harder weeks later. In addition, starting at 2 RIR might cause a bit more muscle damage than we want, and healing from that damage can compete with the same mechanisms that cause growth, so we may end up only healing our muscles and not growing them our best.. It might be best to start easier and work up, so that muscle damage is never excessive. Starting at 2 RIR instead of at 4 RIR is kind of like ignoring a $5 bill laying right next to a $20 bill and picking up only the $20 bill. When you’re already reaching down… you might as well get them both!

In summary for our second reason to overload, we don’t just make training harder to keep it effective, but rather to get all the benefits it offers and average the highest total growth throughout, which means moving from the very easiest, lowest parts of the threshold range to the hardest, higher ones.

What to Progress?

We already know the answer to this is probably “to some extent, everything.” But to what extent? In other words, yes, we should get closer to failure as the weeks go on, add weight to the bar, and add volume, but how much of each? All three equivalently? Or a bias to one or two of them and away from others?

RIR Progression

RIR is up first and luckily, it’s pretty simple. If we hold volume or intensity constant and progress on either, RIR pretty much has to go up if we’re sticking to any kind of rep ranges. More on that later, but the short story is that RIR simply goes up over each week automatically if you increase volume, intensity, or both. If weights are getting heavier and you still need to hit the same reps, or if sets are being added and fatigue goes up over time and you still need to hit the same reps, RIR must go up to keep you hitting those reps. And that’s good news because RIR going up checks RIR off the list!

What does this look like? It can mean that in a 4 week accumulation phase of a mesocycle, you can start at 4 RIR, then move on to 3 RIR, 2 RIR, and finally 1 RIR in the last week before deloading. If your progressions are longer, you can milk out 3 and 2 RIRs for a couple of weeks each. Just remember not to hang out at 4 RIR too long (poor efficiency) or 1 or 0 RIR too long (unsustainable fatigue accumulation).

Intensity Progression

This is the classical, almost default progression. You put more weight on the bar each week in an effort to get stronger. But lately it’s been shown pretty clearly that getting stronger in the short term doesn’t necessarily lead to the best gains in size. In fact, adding more volume in the short term definitely helps size better while long term strength increases correlate very well to long term size gains. Let’s view this another way. We’ve seen studies compare lifting a high percent (85ish) of 1RM vs. a lower one (70%ish) for the same volumes, and with no difference between groups. There are studies that favor higher loads, but they are in the minority and the advantage is usually small. So if we’re promising ourselves bigger muscles if we move from 70% 1RM to 85% in one progression, are we expecting something that might not be in evidence? On the other hand, almost every single study that compares different training volumes shows that, to a point (several studies have discovered a top-end), more volume causes more growth. This is a VERY reliable finding. Oh boy. Does this mean we stop progressing on intensity altogether?

It doesn’t. First of all, adding weight by itself probably causes some small but meaningful size gains. Secondly, keeping reps and sets the same while adding weight does in fact increase volume (as volume is reps x sets x weight), so there’s another benefit. Third, there is some good reason to believe that different rep ranges may target different fiber types more than others or cause growth by slightly different mechanisms. If that’s the case, we need to increase intensity in order to keep our sets in the rep ranges we want them to be in. We can’t have our previous 10 rep sets turn in 15 rep sets because we never increased the load. Lastly, size is very well correlated with long-term strength increases. Combine that with needing to maintain a minimum intensity through the progression, and we have our last good reason to progress on intensity over time.

Notice though, that all of these factors together, especially when taken with the tradeoff of intensity progressions vs. volume progressions, lead us to speculate that intensity progressions should be small. Maybe 5lb on the bar every week, maybe increasing dumbbell weights every 2 or 3 weeks, but nothing much faster than that in most cases. Will you get stronger over time while doing this? Heck yeah! Will it result in great growth? Almost certainly.

Volume Progression

We already saw that holding intensity constant and increasing volume leads to a ton of growth. We are also familiar with the volume landmarks (MEV, MRV), such that we don’t have to search for the “optimal volume” but can instead progress from the lower end to the higher end.

How do we know how much volume to increase by, let’s say, per week? Well, we should be pretty familiar with our MEVs and MRVs after some years of training. Short of more formal analyses, MEV is likely around the volume at which you get some pump, some soreness, and some perception of decent effort in the gym, and not much less than that. MRV is the amount of sets beyond which you’re so fatigued, that the next week your rep strength takes a big hit; more than you’d predict just based on regular fatigue accumulation. Just as example numbers, let’s say your MEV is 10 sets per week and your MRV is 20 sets per week (per bodypart). If you know you’ll be training for 4 weeks before your deload, you can do 10 sets in week 1, 13 sets in week 2, 16 sets in week 3, and 20 sets in week 4, for example. Much like you’d plan a strength mesocycle that goes from 70%1RM to 80%1RM by spacing out the increments weekly, you do the same thing for volume between MEV and MRV.

Are there fancier ways of progression that implement autoregulation? Yes, and they work great. But before you get fancy, getting a grasp of the basics will help you a ton.

If all of this sometimes seems super complicated, here’s the super-simple version:

- Start most programs with 4 RIR and slowly increase your effort.

- Start most programs with chosen weights to hit a spectrum of rep ranges (some sets of 8, some of 12, some of 20, perhaps) and increase weights by small increments to keep those reps similar from week to week as fatigue accumulates.

- Start most programs with a volume you can grow from but isn’t very hard (MEV) and add sets over the weeks until your performance drops (MRV) and you need to deload to drop fatigue.   

- Keep in mind that as far as we know, volume is the king of driving hypertrophy. If you ever change a program variable (intensity, RIR, technique, etc.) at the expense of volume, make sure you have very good reasons.

If you're ready to take the guess work out of progression, let the RP hypertrophy app take all the lead!

For all the information you'd ever want to know about hypertrophy training, be sure to check out the RP Hypertrophy hub!

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