Strength training
RPE and RIR in Lifting: The Effort Scale Explained
Published October 20, 2026
RPE (rating of perceived exertion) is a 1-10 score of how hard a set felt; in lifting it is usually tied to RIR, the number of reps in reserve you had left. RPE 8 means you could have done 2 more reps, RPE 10 means you hit failure. It is the simplest way to adjust your weights to how strong you are on a given day.
RPE to RIR chart
| RPE | Reps in reserve (RIR) | Feel |
|---|---|---|
| 10 | 0 | Could not do another rep |
| 9.5 | 0 (but slightly more weight possible) | Limit |
| 9 | 1 | One more rep |
| 8 | 2 | Two more reps |
| 7 | 3 | Bar speed still good |
| 6 | 4 | Heavy warm-up |
| ≤ 5 | 5+ | Warm-up |
This reps-in-reserve scale was proposed and tested in lifters: their ratings tracked bar speed well, especially in experienced lifters (Zourdos et al., 2016). How to apply it in programs is detailed by Helms et al., 2016.
Why use RPE
- Strength varies day to day with sleep, stress and food; fixed percentages can be too heavy one day and too light another.
- RIR keeps you close to failure without hitting it, protecting technique and recovery.
- Programs become self-adjusting: "3 × 8 at RPE 8" works for everyone.
Which RPE for which goal
| Goal | Exercises | RPE |
|---|---|---|
| Learning, beginner | All | 6-7 |
| Muscle growth | Compounds | 7-9 |
| Muscle growth | Isolation (curls, raises) | 8-10 |
| Strength | Squat, bench, deadlift | 7-9 |
| Deload week | All | 5-6 |
Sample workout using RPE
| Exercise | Prescription | What you do |
|---|---|---|
| Squat | 1 × 5 at RPE 8, then 3 × 5 at −5% | Work up to a 5 with 2 left, then back off |
| Bench press | 4 × 8 at RPE 7-8 | Adjust after set 1 |
| Row | 3 × 10 at RPE 8 | — |
| Lateral raise | 3 × 15 at RPE 9 | Last set nearly to failure |
Learning to rate accurately
Beginners tend to underestimate how many reps they have left. Every 2-3 weeks, on a safe exercise (machine, leg press, curl), take the last set to failure and compare with your guess. Avoid testing failure on squats or bench without spotters.
RPE and progression
If a weight that was RPE 8 feels like RPE 7 the next week, add 5 lb (2.5 kg). That is progressive overload in action: progressive overload. To estimate your max: one rep max calculator.
RPE for running
The same scale doses running intensity: easy runs at 3-4/10, tempo at 6-7/10, short intervals at 8-9/10 (see zone 2 cardio).