Training | POSTED October 31, 2022

You, Me and RPE: Part 1

Rating of Perceived Exertion (RPE) is an autoregulation tool. So, what is autoregulation and why does that matter to you? Autoregulation is a process that takes place within biological systems. It is an automatic mechanism which helps the body adjust to stimuli. A really simple example is perfusion, or the delivery of blood to the capillary beds of organ and skeletal tissue. Without perfusion, oxygen cannot be delivered. At some point, certain tissues require more oxygen in response to a changing stimulus. For instance, there is an increased oxygen delivery to muscles during exercise!

In training, autoregulation is a deliberate and conscious process. It involves adjusting the training demands of the day based on your current ability during a training session. In resistance training, autoregulation is expressed in terms of Rate of Perceived Exertion (RPE), or Repetitions in Reserve (RIR) or Velocity-Based Training (VBT). Autoregulation methods are also used with endurance training. Today we’ll talk about how you can use RPE in your training. Let’s get into it!

What is RPE?

If you’ve ever read an old-school strength program (I mean, who hasn’t, am I right?) then you might have read something like: “6 x 6 @ 70%”. This isn’t witchcraft we promise – it’s simply 6 sets x 6 reps at 70% of your 1 repetition maximum. Your 1 repetition maximum or “e1RM” is the most you can lift for 1 rep (often estimated). Indicating the planned intensity of a session is important as we are trying to deliver a deliberate and effective stimulus. So we need express intensity, but what are the issues with percentages alone?

Well, this prescription relies on a few assumptions. Firstly, you must know your 1 rep max. Secondly, you assume your 1 rep max is a static target. Third and last, strength is specific. Let me use an example to explain. If all you do is 5 reps, you’ll only get efficient with 5 reps. If you start doing 10-12 reps however you may find that using the prescribed percentage is disproportionally hard.

So, there’s clearly some issues with percentages alone.

RPE is therefore simply a rating of an effort, relative to your maximum ability. RPE lets us put language to percentages. Ultimately, it helps us communicate and adjust for how hard something is. It accounts for your e1RM being a moving target and, oh yeah, the fact that humans aren’t machines. Simply put, you won’t always feel your best for a variety of reasons. Training with strict percentages based will limit your options. A static target will mean some days the training is too easy, and other days, too hard.

How can you implement RPE?

Implementing RPE is simple and our companion article will provide a more fleshed out example. Using RPE is as simple as considering how many more reps you could perform once you have finished a set. Second to this is considering the bar speed. This is how quickly you could move a weight during the concentric (shortening) portion of the exercise. For instance, let’s say I was doing a set of squats for 5 reps, and on the last rep while standing up the bar speed slowed down (that is, I stood up more slowly than the first 4 reps). After the set I estimated I could only do about 2-3 more reps before failing, this would be an RPE 7-8.

Importantly, when we consider bar speed we are only counting the “slowdown” that occurs when trying to move a weight as quickly as possible. That is, if the weight is sufficiently challenging and you are working sufficiently hard, that weight won’t be flying around so quickly! In the scientific literature we can call that slowdown a “velocity” loss which reflects intra-set fatigue. Research shows us that there is a sweet spot where we can get strength and hypertrophy outcomes from training while minimising fatigue. This occurs by staying within the 5-8 RPE range which roughly corresponds to a ~20-25% velocity loss [1].

Simply begin to be aware of your training efforts and you will dial in your ability to rate them. Moreover, it seems that the accuracy of your ability to monitor RPE can be improved with practise and exposure [2],[3]. You can use velocity-based trackers for VBT training but this isn’t necessary. What matters most is consistency. So even if your RPE 8 is really an RPE 7, as long as that stays the same, you can anchor your efforts and go from there.

For your convenience, we’ve inserted an RPE chart which also accounts for its inverse, Repetitions in Reserve (RIR). Use this as your reference when deciphering program prescriptions. So returning to that earlier example, instead of the percentage, one could simply write 6 x 6 @ RPE 7 which would mean simply 6 sets x 6 reps each with 3 reps in reserve and some-minimal slowdown. That’s much easier to guess than 70% right?

Wrapping up RPE

Considering your RPE is an important step in making your training more consistent and results, reliable. Poor results can be attributed to many things, but there are two obvious culprits. Firstly, failing to push hard enough. Secondly, pushing too hard, too often. Autoregulation tools such as RPE, RIR and VBT helps trainers and trainees alike find the “goldilocks” zone of not too easy and not too hard. Although learning how to rate your own efforts in training with scales such as RPE/RIR is imperfect, practise will go a long way. Outside of training, occasionally testing to better anchor your perception of a “hard” effort is viable. Testing could include actual 1 rep max tests, training singles or AMRAP (as many reps as possible) sets, all to be discussed at another time.

If you’d like to learn more about RPE and Training, you can read part two here or contact us.

References

  1. The Effect of Load and Volume Autoregulation on Muscular Strength and Hypertrophy: A Systematic Review and Meta-Analysis – PMC (nih.gov)
  2. Methods for Regulating and Monitoring Resistance Training – PMC (nih.gov)
  3. Novel Resistance Training-Specific Rating of Perceived Exertion Scale Measuring Repetitions in Reserve – PubMed (nih.gov)