RPE (rate of perceived exertion) is used for estimating the difficulty level of a physical activity. Lately, some programs utilize RPE instead of percentage-based calculations like on 5/3/1.
RIR stands for "reps in reserve" and usually it's used in the same context as RPE.
This means, if the program says 5 reps at RPE 8 it usually also means that it RIR 2. Essentially saying pick a weight you could lift 7 times but lift it 5 times.
Lost of my favorite programs utilize RPE nowadays. However, lately, I feel a bit confused about merging RPE and RIR. For example, if you leave one rep in reserve on a 4 rep scheme set vs 12, is it the same difficulty? Let's think about this for a moment. With a 4 rep scheme you'll be moving more weight each rep so not doing 1 rep should be a more noticeable drop in difficulty. Also, higher reps usually wear on you more meaning you may feel like a set is RIR 1 whereas it's 2 or even 3.
I think using RPE scale to gauge difficulty and using RIR assessment to understand the proximity to failure makes more sense. As completely separate things.
However, there is no better method to understand what RPE ratings mean than RIR. If so I will stick to a rep range, preferably 10. In this case, RIR X will equal to RPE 10-X.
Luckily 6-8 rep range is at the lower end of the hypertrophy spectrum and is at the high end of the strength spectrum.
Since you won't be performing RPE 10s left and right all the time in the gym it fits perfectly. RPE 8 will be choosing a weight that you can do a maximum of 10 reps and doing only 8. Easy to calculate and seems to work for a lot of people.
As a side note, I understand technically RIR and RPE can be the same thing however please do remember that, the main drawback of the RPE system is its accuracy and with changing rep ranges you'll be aggravating the problem, here's how.
You take 60% of your 1RM and go AMRAP you might hit a point around the 15th rep that feels like RPE 9 since you're used to training with lower rep ranges previously. Whereas after the 15th rep, you might go for another 7. All 7 will feel like RPE 9 - 9.5 and will be very difficult as they should. So how can 7 RIR correspond to RPE 9?
One possible solution to this is to remember what RPE ratings feel like on different rep ranges but memorizing it and assessing accurately even for one rep range is a challenge on its own.
In short, I add or remove weight from the bar to keep my rep scheme fixed at 10 reps. That is the main purpose. If I go for RPE 8 at the 8th rep as programmed previously and it feels like RPE 6 I count that as a warm-up set and add weight until RPE 8 is the 8th rep.
If for whatever reason I need to work on rep ranges that are far away from 10 I just aim for 2-3 RIR and most likely get away with it just fine.
Please be advised that I am not a licensed medical professional or a certified fitness trainer. The information presented on this blog is solely for informational purposes and should not be misconstrued as medical advice. Before embarking on any new exercise regimen, way of performing an exercise or dietary changes, it is crucial to seek guidance from your healthcare provider. Always prioritize your physical well-being and discontinue any activity that causes discomfort or pain. This blog serves as a platform for sharing personal experiences and perspectives, not as a substitute for professional medical or fitness advice. Please exercise due diligence and consult with a qualified healthcare professional before making any significant changes to your health and wellness routine.
