RPE & RIR: Control your training intensity.
Understand the two most important scales for subjective effort — and why they make your training better than fixed percentages.
The RPE Scale (6-10)
| RPE | RIR |
|---|---|
| 10 | 0 |
| 9.5 | 0-1 |
| 9 | 1 |
| 8.5 | 1-2 |
| 8 | 2 |
| 7.5 | 2-3 |
| 7 | 3 |
| 6 | 4+ |
Maximum — no more reps possible
Bench press: 100kg, last rep barely completed
Could maybe have done one more, uncertain
One more rep? Maybe. But probably not.
Could have done 1 more rep
Squat: 120kg x 5, one more would have been possible
Definitely 1 more, maybe 2 reps
Challenging but controlled
Could have done 2 more reps
Deadlift: 140kg x 3, two more would have been there
Definitely 2 more, maybe 3 reps
Tough but bar speed was still good
Could have done 3 more reps
OHP: 50kg x 8, three more no problem
Warm-up intensity, light effort
Like a warm-up set with a bit more weight
What is RIR?
RIR stands for Reps in Reserve — how many more reps you could have done. RPE 8 = 2 RIR means: You could have done 2 more reps.
RPE → RIR (Reps in Reserve)
Why RPE is better than fixed percentages
Your 1RM fluctuates daily — RPE adapts, percentages don't
On bad days you train lighter, on good days heavier
You learn to judge your body better
Less injury risk from ego lifting
How to use RPE in training
Instead of '4 sets at 80kg' you plan '4 sets at RPE 8'. That means: you pick a weight where you still have 2 reps in the tank at the end. On good days that's 85kg, on bad days 75kg. Your body drives — not the spreadsheet.
Common mistakes
Ego-RPE: You say 'RPE 8' but it was actually RPE 10. Be honest with yourself.
Too early: Beginners can't judge RPE well. Only meaningful after 6+ months of training.
All RPE 10: If every set is maximal, you don't recover. Most working sets should be RPE 7-8.
RPE in strength training: The scientific basis
The RPE scale (Rate of Perceived Exertion) used in strength training is based on the Borg CR-10 scale, adapted by Mike Tuchscherer for powerlifting. It has been used by elite athletes and coaches worldwide for over 15 years.
A study by Helms et al. (2018) directly compared RPE-based training with percentage-based training in experienced lifters. The result: Both methods produced comparable strength and hypertrophy gains — but the RPE group trained with less total volume and reported less fatigue. RPE can deliver the same results with less work.
The key lies in honesty with yourself. Beginners (under 1 year of training experience) regularly misjudge their RPE by 2-3 points. That's why most coaches recommend only starting RPE after at least 6 months of consistent training. Until then, fixed percentages are the safer path.
For advanced lifters, RPE is an indispensable tool — especially combined with percentage-based programs like 5/3/1. Percentages provide structure, RPE provides flexibility. This combination is the standard in modern strength training today.
Sources
- Zourdos MC et al. (2016). Novel Resistance Training-Specific RPE Scale Measuring Repetitions in Reserve. JSCR, 30(1):267-275.
- Helms ER et al. (2018). RPE and Velocity Relationships for the Back Squat, Bench Press, and Deadlift. JSCR, 32(2):292-297.
- Tuchscherer M. Reactive Training Systems Manual.
This is built into hitPR.
In the hitPR app, you can track RPE and RIR on every set. Over weeks, you'll see how your training intensity develops.
Track RPE in your workout