RPE vs RIR: How to Use RPE Instead of RIR in a Workout Log
Start with one clear effort language
RPE, or rating of perceived exertion, is a 1 to 10 score for how hard a set felt. RIR, or reps in reserve, estimates how many clean reps you could still have completed when you stopped. Both describe effort. They simply count from opposite ends.
For lifting logs, the practical translation looks like this:
| RPE | RIR equivalent | What it means |
|---|---|---|
| 10 | 0 | No clean rep was left |
| 9 | 1 | One clean rep was left |
| 8 | 2 | Two clean reps were left |
| 7 | 3 | Three clean reps were left |
| 6 | 4 | Four clean reps were left |
| 5 or lower | 5 or more | Far from your limit |
This is a useful working map, not a laboratory measurement. RPE 8 does not guarantee exactly two extra reps on every exercise, rep count, or training day. It gives your coach a consistent language for interpreting your estimate.
RPE vs RIR is mostly a translation problem
If your program is written with RIR targets but you prefer entering RPE, you do not need to change the program. Use the same 1 to 10 RPE scale every time, then convert it to the matching RIR value behind the scenes.
A target of 2 RIR becomes RPE 8. A target of 1 RIR becomes RPE 9. A set taken to technical failure, meaning you could not complete another rep with the planned technique, becomes RPE 10.
The important part is not choosing the perfect label. It is making RPE 8 mean roughly the same thing next week as it meant today. An adaptive coach can work with an estimate that is consistently a little high or low. It cannot do much with ratings that change meaning from set to set.
Use the lifting 1-10 scale, not a mixed scale
Most strength logs use a 1 to 10 effort scale. Some athletes know the older Borg scale, which runs from 6 to 20. Do not mix the two. A 7 on a 1 to 10 lifting scale usually means about three reps left. A 7 on the Borg scale means something entirely different.
Whole-number RPE entries are usually enough. Use half points when they add useful detail, such as RPE 7.5 when a set felt clearly harder than 7 but not close to 8. Do not turn every set into a debate between 7.5 and 8. The estimate is already subjective.
Rate the set you completed, not the effort you expected before starting. If you planned eight reps and completed eight at RPE 9, log RPE 9. If the same eight reps felt like RPE 7, log RPE 7. Your completed performance and actual effort are the feedback an adaptive coach needs.
Log the full set, not only the effort score
RPE becomes useful when it is attached to the rest of the set. At minimum, record:
- Exercise
- Load and unit
- Completed reps
- RPE
- Set number, when set order matters
A clean entry looks like this:
Bench press, 80 kg x 8 @ RPE 8
That tells a coach much more than bench felt hard. It can translate RPE 8 to roughly 2 RIR, compare the same load and reps with earlier sessions, and see whether effort is rising or falling.
If your reps change, report the actual number. 80 kg x 7 @ RPE 9 is different data from 80 kg x 8 @ RPE 9. If technique also changed, note that briefly. A shorter range of motion or a faster tempo can make an old RPE number look like progress when the set standard moved instead.
Give the adaptive coach one canonical effort signal
Do not enter both RPE and RIR unless your app specifically asks for both. They are two labels for the same estimate, and entering both can create contradictions. You might type RPE 8 and 1 RIR without realizing those values disagree.
A better system stores one primary value. If you prefer speaking RPE, enter RPE and let the coach convert it internally to RIR. If a plan is built around RIR, the coach can still compare your feedback against the target without asking you to use a scale that feels unnatural.
GymLog users can say the exercise, load, reps, and RPE after each set. For example: Incline dumbbell press, 30 kilos each hand, 10 reps, RPE 8. The exact wording matters less than repeating the same structure across sessions.
The coach should also compare like with like. RPE trends are most useful when the exercise, rep target, load, technique, and broad training conditions are similar. One unusually poor night does not prove that your strength dropped. Two or three similar sessions provide a better signal.
Use RPE trends without overreacting
Imagine three bench press sets at 80 kg:
- Set 1: 8 reps at RPE 7.5, about 2 to 3 RIR
- Set 2: 8 reps at RPE 8, about 2 RIR
- Set 3: 7 reps at RPE 9, about 1 RIR
This tells a different story from three sets of eight at RPE 8. The final set lost a rep while effort climbed. An adaptive coach can treat that as accumulating fatigue and avoid assuming that the first set represents the whole session.
Now compare the same work across weeks. If 80 kg for eight reps moves from RPE 9 to RPE 8, you likely have more room to add training demand. Progressive overload, the gradual increase in training demand, might mean adding a small amount of load or completing another rep, depending on your plan.
Do not make that change from one rating alone. Check whether reps were completed to the same standard and whether the lower RPE repeats across at least two sessions. A lower rating with shorter range of motion is not the same improvement as a lower rating with identical technique.
Avoid the common RPE logging mistakes
Rating discomfort instead of effort: A high-rep set can burn badly while still leaving several clean reps. RPE should describe how close you were to your limit, not how unpleasant the set felt.
Treating RPE 10 as normal: Save RPE 10 for a set where another clean rep was not available. If you use 10 for every difficult set, the scale loses its upper limit and your coach loses useful separation between hard and maximal work.
Changing your standard mid-session: Decide what counts as a rep before the set. Depth, pause, range of motion, and control should stay comparable when you are using effort trends to guide decisions.
Logging only the final set: Each set shows how effort changes as fatigue builds. Logging all planned work sets gives the coach a clearer picture than one end-of-session score.
Using vague words instead of a number: Hard, fine, and easy can mean different things to different people. RPE 8 is not perfect, but it is easier to compare and translate.
Use this simple RPE logging script
After each work set, ask yourself one question: how many clean reps could I have done with the same technique?
Then enter the inverse number on the 1 to 10 scale. One rep left is RPE 9. Two reps left is RPE 8. Three reps left is RPE 7.
Your final log can stay simple: exercise, load, completed reps, RPE. Use that same format every session. RPE is not replacing useful training data. It is a faster way to express the same effort information as RIR, while giving an adaptive coach a stable signal for future adjustments.