Understanding Training Effort

What is Effort?

It can be very difficult to know whether you’re pushing your sets sufficiently hard to maximize progress. While the term effort (also commonly referred to as exertion) may seem obvious, it’s a fairly vague term which often leads to confusion. In the context of hypertrophy and strength training, effort refers to proximity to muscular failure. “Muscular failure” rather than generic “failure” is a critical distinction to understand, as different sensations can obscure how close to failure you feel like you’re actually training. The rep range, exercise, exercise order, etc. will significantly influence how it feels, but we want one thing to remain constant - how far away from failure you’re going. 

Although they’re related to muscular fatigue, we’re NOT directly concerned with the following when considering effort:

  • Global fatigue (how hard it feels like your entire body is working)
  • Cardiovascular failure (how out of breath you’re getting)
  • How much pain/strain you’re experiencing
  • How pumped your muscles are getting 
  • How much you’re sweating

With this in mind, there are two primary methods we use to subjectively measure effort for each set:

Reps in Reserve (RIR):

Reps in reserve is a system which has you estimate how many additional reps you’d be able to perform at the end of your set. According to the scientific literature, RIR becomes very vague at high values - in other words, the more reps you have left in the tank, the less reliable the system is.

The easiest way to conceptualize this would be imagine if you’re doing a 10-rep max, your RIR scale would look at follows:


Additional reps you could’ve done: 


0 additional reps - max effort


1 additional rep


2 additional reps


3 additional reps


4 additional reps


Starts to become too low of effort to discern


It’s important to note that a 0RIR doesn’t necessarily mean you actually failed the lift, it just means you couldn’t do an additional rep. Some people will consider failing a rep as a -1RIR, although that’s not something you want to regularly do.

As a personal note, I find reps in reserve tend to make more sense with compound exercises, where the goal is to maximize strength in various rep ranges.  

Rate of Perceived Exertion (RPE):

Rate of perceived exertion (or effort) is a scale of 1-10, with 10 being 100% maximum local (muscular) effort within a set, and every decreased point being roughly 10% of your effort. In other words, you’re trying to estimate roughly the percentage of how hard the relevant muscles worked on an exercise, NOT how hard your entire body worked. 

Similar to reps in reserve, RPE tends to not be as useful for very low levels of effort. A scale of would look as follows:


Percentage of your maximum effort 


100% - max effort


90% of max effort


80% of maximum effort


70% of maximum effort


60% of maximum effort


Starts to become too low of effort to discern


Although counterintuitive, the percentages associated with RPE do NOT reflect the percentage of the load you should be lifting. The best way to understand this is by looking at an example: if you did your 1 rep max, it would be an RPE10, however, if you wanted to deload with an RPE6 for 1 rep, using 60% of your max would be a bit too light. There’s no perfect translation between RPE and percentage of load you should be lifting, but it’s something you’ll get better with over time. 

I find RPE tends to work better on isolation lifts, where strength isn’t as much of the driving factor of hypertrophy, but you’re still wanting to appropriately pace your workouts to avoid training too hard early on in a training block.

Additionally, Bret tends to use “Session RPE” as a gauge of how hard your overall workout felt once you’ve completed it. It’s a great tool for gauging your overall recovery, along with volume & effort tolerance. The mandatory workouts of Booty by Bret is designed to wave load the session RPE (week 1 should have each session with an RPE of 6-7, then incrementally increasing up to a session RPE9-10 on week 4). With that in mind, modify the loads (and potentially number of sets) to appropriately deload if you’re feeling like the session RPE is too high to start out with, or alternatively, scale the load up if you feel like you’re not training hard enough. The optional Pump Days (formerly called Glute Days) are intended to have a considerably lower session RPE throughout the month, allowing you to stimulate the muscle groups being worked while minimizing recovery demands.

How to Learn Your RIR/RPEs:

Both RIR and RPE are subjective methods which take some time to develop to the point where they are reliable. Since the frame of reference of both of them is actually going to failure (0 reps in reserve / 100% of maximum exertion), it’s important to train to failure every so often to ensure you’re not underestimating yourself. Booty by Bret will almost always include some form of AMRAP (as many reps as possible) sets, which by definition, you’re doing a 0RIR/RPE10. During weeks 2 and 3 in particular, briefly try to guestimate how many more reps you could’ve done at the end of your set. Over time from guessing an RIR or RPE, then putting it to the test during AMRAPs and PR sets on week 4, you’ll start to find it very beneficial for assessing how hard you’re pushing yourself.

How Hard Should You Train?

The scientific literature is very clear that training at high effort is best for hypertrophy, especially the more lifting experience you have. In recent years, there’s been a lot of debate on whether or not you should train to failure (0RIR or RPE10). The science doesn’t strongly point in either direction, however, chronically training to failure can unnecessarily risk injury with little-to-no gain. Anywhere between the 1-3RIR range seems to be similar for hypertrophic outcomes, with the only caveat being training with loads ≥ 30% of 1RM, going to failure seems to hold a clear advantage over not (this is particularly important for at-home training).

How Do You Know if You’re Training Hard Enough?

If you’re new to pushing yourself to muscular failure, it’s very common to underestimate your strength by a significant amount (and as someone who has learned from, worked for, and seen train clients, I can attest to Bret’s strongest trait as a strength coach is his ability to get people to realize just how strong they are and how hard they can push themselves). 

Here’s a general guideline to tell if you’re estimating your effort appropriately:


Going to Failure (0-1RIR or RPE9-10):

High Effort (1-3RIR or RPE7-9):

Deloading Effort (3-5RIR or RPE5-7):

Bar speed:

Even if you’re pushing as hard as you’re able to, you’ll notice the weight you’re using will decrease significantly, often with your muscles trembling, with an 0RIR risking actually failing on the lift

On the few reps, you’ll start to notice the speed of the weight you’re lifting is starting to slow down and you’re having to focus a bit more than usual, but you’re not risking actually failing the lift

The weight should move very mechanically with little to no change in how fast the bar is moving


Depending on the lift, you’ll need 2-5 minutes to fully recover from pushing yourself this hard due to your muscles still feeling fatigued

Depending on the lift, you’ll likely need 2-4 minutes between each set in order to replicate your strength

You shouldn’t feel like you need to take all the much rest between sets in order to replicate your strength, although we still recommend taking more time to let your body truly recover (you don’t want to decrease the load but increase the cardiovascular demands when hypertrophy is the goal) 


It’s unlikely you’ll be able to replicate the amount of reps * load in subsequent sets due to how demanding very high effort is

You’ll find by the 3rd set, you’re starting to feel yourself struggling to use the same load, but you should be able to manage without having to lighten the load

Your last set should feel roughly as challenging as your first set without changing the load


You’ll start to notice a bit of form breakdown. While you don’t want to let it degrade too much, it’s expected to have minor form deviation while training to your limits. If your form deviates significantly before you’re able to achieve “true” failure, this is called form failure

Your form will mostly stay strict, possibly getting ever so slightly loose on the last rep.

Deloading allows you to work on your form without having to worry about performance whatsoever, so aim to make your form as perfect as possible and familiarize yourself with any potentially new lifts.


In order to work to your “true” maximum effort, you’ll want to be very focused, motivated, and mildly aggressive going into the set while still keeping your mind on form. 

You should go into these sets focused and ready to lift very hard, however, you shouldn’t need to hype yourself up too aggressively 

You should feel like you’re borderline not doing enough in the gym. If you find yourself getting overly hyped up, you might be lifting slightly too hard

Compound Lifts

With 0-1 RIR, this will typically be right around a recent PR for you



Isolation Lifts

For RPE10, you’ll likely feel a muscle group burning very intensely, possibly getting an intense pump




What About Soreness? 

I intentionally didn’t mention muscle soreness as a factor, as it's not directly tied to effort. A very common misconception is that if you’re not getting sore, you’re not pushing yourself sufficiently hard. DOMS is not a very good predictor of how effective your workout is for building muscle and is more commonly associated with exercise novelty (don’t be surprised if you get sorer on week 1’s deload compared to week 4’s max effort week) and muscle damage.