Training
A percentage of your one-rep max assumes every day is the same day. RPE is how you train correctly on the days that are not.
RPE is rate of perceived exertion, scored 1–10. In lifting it is used as reps in reserve: RPE 8 means you could have done two more reps. Most productive work sits at RPE 7–9, which is close enough to failure to grow and far enough from it to repeat.
| RPE | Reps in reserve | What it feels like |
|---|---|---|
| 10 | 0 | Could not have done another rep |
| 9.5 | 0–1 | Maybe one more, certainly not two |
| 9 | 1 | One clean rep left |
| 8 | 2 | Two left; bar speed clearly slowing |
| 7 | 3 | Hard, still moving well |
| 5–6 | 4–6 | Warm-up or technique work |
Because your one-rep max is not a constant. Sleep, stress, food, time of day and where you are in the week can move what 80% actually feels like by two reps in either direction. A programme written in percentages asks for the same thing on your best and worst days; a programme written in RPE asks for the same effort, which is what drives adaptation.
On a bad day, RPE 8 might be 90 kg instead of 100. You still did the productive work. The percentage-based version would have had you grind out a failed set and pay for it all week.
Stopping one to three reps short produces similar growth to training to failure with substantially less fatigue — which lets you do more quality work across the week. That trade is the entire argument for RPE 7–9.
Beginners consistently underrate: a set logged as RPE 8 is often a genuine 6. Two things fix it quickly. First, occasionally take a set to true failure on a machine so you have a real reference for 10. Second, watch bar speed — the rep where the bar visibly slows is usually RPE 8, and this is far more reliable than how hard it felt.
RPE is most useful as a record, not a target. If last week’s 3×8 at 80 kg came in at RPE 7, the weight is ready to go up. If it was RPE 9.5, repeat it. That is the progression decision made from data rather than optimism.
RPE stands for rate of perceived exertion, a 1 to 10 scale describing how hard a set was. In weight training it is usually interpreted as reps in reserve: RPE 8 means you could have completed roughly two more reps before failure.
Most working sets belong at RPE 7 to 8, with an occasional RPE 9 as a top set. This is close enough to failure to drive growth while leaving enough capacity to repeat the work across the week.
For most people, yes, because a one-rep max varies day to day with sleep, stress and nutrition. RPE asks for consistent effort rather than a fixed load, which keeps sessions productive on both good and bad days.
Beginners typically underrate effort. Take an occasional set to genuine failure on a machine to calibrate what 10 feels like, and watch bar speed: the rep where the bar visibly slows is usually around RPE 8.
RPE is only useful if it is recorded next to the set it describes. NutriMacro logs RPE alongside sets, reps and weight, and surfaces last week’s rating when you come back to the same exercise.
NutriMacro is a nutrition and training tracker for iPhone and Android. It logs food by barcode, photo or search, counts food in slices and units rather than grams, and keeps strength training, GPS activities, sleep and recovery in the same daily view. It runs in the language of your phone across 108 countries.
General training guidance for healthy adults. If you have an injury, a health condition or are new to lifting, get coaching on technique before chasing load.
Read next: When to add weight Reps vs weight What is progressive overload?
