What are RPE and RIR?
If you have been training for any significant amount of time, you’ve noticed that there are different prescriptions out there for how to adjust the load or intensity of a movement. Traditionally, using a percentage based prescription has been the standard. For example, performing a 3x3 Back Squat at 90% of your 1 repetition max (1RM). This can be an excellent tool for writing programs but lacks some flexibility when we account for day to day fluctuations in recovery, sleep quality, life stress, etc.
This is where RPE and RIR have come to the forefront of writing workouts.
RPE stands for Rate of Perceived Exertion. This scale can help determine your intensity in a given set based on how you feel that specific day. For example, a RPE of 10 means maximal effort. This in theory should equate to your 1RM for a given lift in a set of 1 rep. Another example is on the other side of the scale where a RPE of 1-2 for any set would be little to no effort to perform the lift. This gives the athlete some flexibility in choosing their weights in a session. In my opinion we need this flexibility because in a training session, an athlete might not be able to hit a “true” 10 RPE on a lift (or their 1RM) if they are poorly recovered. Instead they could perform a 10 RPE for that day which might only amount to 90-95% of their actual 1RM.
The table below (Helms) shows us what a “true” RPE prescription means in terms of percentages.
RIR, which stands for Repetitions in Reserve, is another scale you might see on a workout program. This essentially means the number of additional repetitions you could perform at the end of a given set. A 1 RIR prescription means that at the end of your set, you feel like you could only do 1 more rep, or you only have 1 rep in reserve. This allows you to adjust the loading to meet the number of reps intended with a little less subjectivity. This is especially true for experienced lifters.
Studies show that experienced lifters (lifters with >1 year experience with a given lift) are fairly accurate at predicting how many additional reps in reserve they could perform and are less accurate at rating their perceived exertion on a set. This means that it would be advisable to use the RIR scale vs the RPE scale.
That being said, if we understand how both scales relate to each other, we can use both scales and still hit the correct stimulus. The table below (Helms) is a great resource and can give us an idea of what different RPE prescriptions mean in terms of RIR training.
Hopefully this has provided a little clarity on how we can accurately use the RIR and RPE scale a little better when we are choosing weights in the gym!
Happy Training!
-Coach John
Source:
Helms ER, Cronin J, Storey A, Zourdos MC. Application of the Repetitions in Reserve-Based Rating of Perceived Exertion Scale for Resistance Training. Strength Cond J. 2016 Aug;38(4):42-49. doi: 10.1519/SSC.0000000000000218. Epub 2016 Aug 3. PMID: 27531969; PMCID: PMC4961270.