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This is a guest post by Dr Mike Israetel, Head Science Consultant at Renaissance Periodization and one fifth of Juggernaut Training Systems. Mike is a Bodybuilder, Scientist, advisor to several Olympic athletes, former powerlifter and two-time Arnold Grappling Classic Jiu Jitsu Champion. Check our podcast interview with him here.

What is MRV?

It’s the most volume you can recover from, usually defined as recovery from one microcycle to the next. What is recovery? In this context, it’s the return to your usual performance abilities within the fitness characteristic in question.

In the case of MRV, you are “recovered” if you’re performing comparably in this microcycle to how you did in your previous microcycle. So, the way you know that you’ve exceeded your MRV is simple: you underperform in this microcycle as compared to the last one.

Other details can add more colour to the picture, but that’s the fundamental way to tell whether or not you’re over your MRV. If a drop in performance suggests that you’ve exceed your MRV in your most recent micro, but you did not experience a similar drop in the previous micro, you know your MRV is likely between the volume of the second-to-last micro and the last micro.

How would this work in the context of hypertrophy training?

Before we give an example, let’s remember that hypertrophy training is fundamentally based on increasing weights, as well as total reps done at those weights, at an average of 7 to 15 reps per set.

Your 5×10 PR on squats isn’t an exact indicator of how much muscle you have in your quads, but it’s a damn good one. And if that value goes up over time, you can almost bet that hypertrophy is largely responsible. So how do you know you’ve hit your MRV? Let’s say that your usual best effort on the bench press – where you’re maybe a rep shy of failure – on any given day when you’re recovered is 225lbs for 4 sets of 10. Let’s say you do a 5-micro accumulation phase and it ends up looking like this:

Micro 1: 215 for 10,10,10

Micro 2: 220 for 10,10,10,10

Micro 3: 225 for 10,10,10,10,9

Micro 4: 230 for 10,10,10,9,8

Micro 5: 235 for 10,10,9,9,8,8,7

You deload after this accumulation phase, and then you look back at the mesocycle. Did you pass your MRV at any point? How would you know? Well, passing MRV means not being able to recover. Which means a performance drop from one micro to another. If you look at all of the adjacent micros and compare them to each other, does it look like performance ever dropped? Yes, the reps went down, but that’s when the weight went up. And the reps dropped as an expected function of the weight increase, based on our initial performance benchmark. In other words, it’s not likely that the MRV for bench pressing for reps – a good proxy for chest hypertrophy MRV – was exceeded, even with the 6 sets of benching in Micro 4.

Let’s say we deload, and then want to continue the search for our MRV. What do we do now? Well, since we know we didn’t hit our MRV with ~ 6 sets, it appears we must go higher. So we start a bit lower, and work past the old volumes:

Micro 1: 220 for 10,10,10,10,10

Micro 2: 225 for 10,10,10,10,9,9

Micro 3: 230 for 10,10,10,9,9,8,8

Micro 4: 235 for 8,7,7,6,6,5,5,4

Micro 5: 240 for 5,5,4,4,3,3,3,2,1

Notice that we raised the average weight being used in order to account for some of the adaptation gains in the last mesocycle and to expand this experiment from a search for MRV to a productive hypertrophy cycle as well.

But notice what happened this time.

Micro 2 was a full recovery from Micro 1. Micro 3 was a full recovery from Micro 2. But something definitely changed between Micros 3 and 4.

The reps of Micro 4 were not as high as you’d expect if we simply extrapolated current rep strength to that load. It’s definitely possible that the 7 sets of Micro 3 were just around the MRV for this particular individual in these particular conditions, and that the 8 sets of Micro 4 were now in excess of that value. And, sure enough, the rep performance of Micro 5 is even more of a drop-off from usual abilities. You’d expect someone who can hit 225 for 4×10 to hit 240 for sets of 8 or so, not 5s and fewer.

That’s almost certainly under-recovery, which means that MRV of around 7 sets in this example is a distinct possibility.

But, before we can conclude that 7 sets is very likely the MRV, we have to account for and do something about two potential sources of estimation error, namely: acute fatiguing events and cumulative fatigue.

What if your training is going well, but then your boss announces: “We have to meet in my office next week for a very serious discussion.” Worried about this looming “talking to,” you spend the rest of the week barely sleeping, under-eating, and stressing your ass off. Your fatigue skyrockets, and your recovery ability plummets.

Your training performance goes down the drain that week, and, assuming that you hit your MRV, you plan to deload starting on Monday of the next week due to decreased performance. On Monday, you finally have the meeting with your boss, fearing the worst.

He rants and raves to you about how Phil, the firm’s VP, quit on him without notice last week, and to your amazement, you’re now being promoted to the VP position, which will double your salary and vacation time. You walk out of the meeting feeling like a zillion bucks. You’re still super tired from freaking out all of last week, but you’re infinitely relieved as well. So, given all of this information, do you think you hit your MRV? Well the true answer is that you can’t be sure. It’s possible that you did in fact hit it the week your boss brought up “the talk”, causing your performance to decline, because, for all we know, your performance would have declined regardless of this incident.

But, on the other hand, you may have been a long way off from your MRV, and the main reason you overreached is that the incident itself added a huge dose of fatigue. And, because fatigue is cumulative, it’s simply not the case that once your anxiety was replaced with relief – poof! – all of a sudden, you’re back to usual performance levels. Until you deload, your performance will still be reduced, because the fatigue summed from the weeks of training and the stressful incident lingers, and takes time to dissipate.

The worst part is, you don’t know how much fatigue was induced by that incident, and how much was induced by training, so you’re still in the dark about your MRV.

Because acute fatigue events such as described above leave fatigue hanging around, it can take a full deload to disappear. The other problem for the accuracy of our MRV estimation is that fatigue is cumulative. Let’s say you have an accumulation phase that begins with 3 sets of work and you raise your volume by a set each micro. But let’s say your actual MRV is 12 sets per week, which would mean that it would take around 10 weeks of accumulation to reach it! But how much cumulative fatigue would be present by, say, week 10? That’s ~ 8 weeks of accumulation training, the latter half of which would be particularly fatiguing.

By week 10, you might have so much fatigue that your performance begins to drop off, and you never get to your actual MRV under more normal accumulation cycle lengths. You’ve now erroneously underestimated your MRV, because you ran such a long accumulation phase that cumulative fatigue sapped your recovery ability reserves, making your MRV appear lower than it is.

How do we obviate these two confounders: acute fatiguing events and cumulative fatigue?

The answer is: we have to run multiple mesocycles of MRV testing. Each time we find our “possible MRV” for a mesocycle, we deload, and then repeat the next meso by starting a bit higher in volume and intensity than the last. After 2-5 such mesocycles, the likelihood of chance events infecting every single run is low, and the cumulative fatigue problem is reduced. The latter is due to the fact that, while we may have started some earlier mesos 5-6 micros of volume increases under our MRV, the more recent ones might only have been started 2-3 micros under our MRV. What would this look like for our bench press example?

Well, after several mesos, your performance seems to drop somewhere between 6 sets and 8 sets. 6 sets represent the times you started the meso with only 2 sets per micro, and that other time you had that incident at work. 8s represent the time you had that amazing training cycle because your sleep and eating were super consistent, and the new position at your job was super rewarding and low stress. After that tight range of 6-8 becomes apparent and repeats itself over and over, it becomes pretty clear that your true average MRV is probably right around there somewhere!

That’s the formal method, but do we have to be so formal about things and deviate so far from our normal training to find our MRV?

Absolutely not.

Fundamentally, we can get a great estimate by simply starting each training cycle with a volume we pretty much know for sure isn’t pushing our limits, though is challenging enough to give us some gains. As the cycle progresses, we slowly increase volume until we’re unable to recover, then deload, and then rinse, repeat. Two pieces of great news for this method: first, you find your MRV this way, and second, that’s how you’re supposed to be training for hypertrophy anyway!

Once you do find your actual MRV and know it reliably, you can plan most of your mesocycles to end right at or just over that number for Functional Overreaching benefits, and that’s that! As your MRV changes over time, say by going up slowly, you’ll notice that you’re not nearly as fatigued in that last week as you’re used to being, so you might go an extra week here and there, or start the next meso with slightly higher volume, and see how things go.

By doing that when you’re not feeling maximally challenged in your last week, you’re making sure to keep your training in step with your evolving MRV.

For hypertrophy, fitness sport, and endurance, this method works very well, because volume jumps are part of the training for these sports/characteristics. But what about the training for characteristics like speed, power, and strength, for which volume doesn’t typically increase during the mesocycle, and might even slightly decrease to accommodate bigger jumps in intensity? It’s much the same process, but adapted to tracking intensity instead of set numbers. For example, if you’re doing sets of 3-5 reps every week for strength, you can start with 300lbs on the squat for 4 sets, and go up by 10lbs each week without adding sets. You’ll eventually get to a microcycle that might have you drop from something like 330 for 4 sets of 4 with one rep left in the tank to 340 for sets of 3,2,1,1, with all of those being “no way I could do more” grinder reps. In this case, your MRV for around 330lbs is likely around 4 sets, and multiple reapproaches to that weight/rep neighborhood over the next several mesos will confirm this.

Similarly with power, if you start reliably missing cleans and snatches at some volume/intensity intersection, then that’s likely close to your MRV for that intensity. If your speed on the track starts to decline after a certain number of sprints per week, or a certain number of max-effort sprints, you know that you’re getting a feel for your MRV!

To boil the search for your MRV down to the simplest principles possible: make sure to regularly challenge yourself in your training, and note when performance drops off.

Always deload right after it does, as training above your MRV is a very bad idea for prolonged periods, and re-cycle back from lower volumes or intensities in the more explosive characteristics like power or strength, to resume working towards your limits. If you collect good data and keep good track of your training, you’ll have a good approximation of your MRV.

Is it going to be an exact approximation?

No way.

But who needs one of those?

MRVs will change little by little on a regular basis anyhow, based on multiple influences.

Hence, just getting a general understanding – like whether your MRV is at 10 sets per week of back work, or more like 15 per week – is going to inform intelligent training design.