RPE and RIR Scale: Complete Guide to Measure Your Effort in Weight Training
Question: What are RPE and RIR in weight training?
Answer: RPE (Rate of Perceived Exertion) measures perceived intensity from 1 to 10. RIR (Reps In Reserve) indicates how many more reps you could have done. Simple formula: RPE = 10 - RIR. Example: if you could do 2 more reps, you are at RIR 2 = RPE 8.
🎯 Why Use RPE/RIR?
1RM percentages (maximum load) are imprecise day-to-day. Your form varies based on sleep, stress, and nutrition. RPE/RIR adapts to YOUR state on any given day.
Benefits of RPE/RIR
- Self-regulation: adjust effort based on how you feel that day
- Overtraining prevention: avoid pushing too hard when you are tired
- Optimal progression: find the sweet spot between stimulus and recovery
- Works anywhere: no need to calculate percentages
📊 The Complete RPE Scale
RPE 10 - Total Failure (RIR 0)
- Feeling: Impossible to do one more rep
- Use: Strength tests, rarely in training
RPE 9 - Very Hard (RIR 1)
- Feeling: Only one rep left in the tank
- Use: Occasional heavy sets
RPE 8 - Hard (RIR 2)
- Feeling: 2 reps clearly left in reserve
- Use: Ideal zone for hypertrophy
RPE 7 - Moderate (RIR 3)
- Feeling: 3 reps in reserve, starting to feel it
- Use: Strength while preserving explosive qualities
RPE 5-6 - Light (RIR 4-5+)
- Feeling: Work is noticeable but not hard
- Use: Warm-up, technique work, active recovery
💪 Optimal Zones Based on Your Goal
For Hypertrophy (Muscle Building)
- Target RPE: 7-9 (RIR 1-3)
- Why: Sufficient stimulus without excessive fatigue
- Study: Pareja-Blanco (2020) shows that VL 30-40% optimizes hypertrophy
For Maximum Strength
- Target RPE: 7-8 (RIR 2-3)
- Why: Preserves RFD (explosiveness) while stimulating strength
⚠️ Common Mistake: Going to Failure Every Time
Many lifters think they need to hit RPE 10 (failure) on every set to progress. This is wrong and counterproductive.
What Science Says (Pareja-Blanco 2020)
- VL 40%+ (RPE 9.5-10): Decreases early RFD (explosiveness)
- VL 20-40% (RPE 7-9): Optimal zone for BOTH strength AND hypertrophy
- Conclusion: Stop 1-3 reps short of failure on most sets
📱 Smart Rabbit and Self-Regulation
Smart Rabbit integrates RPE/RIR into its generated programs. The app asks about your fatigue level and automatically adjusts the recommended intensity.
Generate Your Personalized Program
Smart Rabbit creates programs that adapt to YOUR level and YOUR recovery. Try it for free!
Try Smart Rabbit❓ Frequently Asked Questions
What is the difference between RPE and RIR?
RPE (Rate of Perceived Exertion) measures overall intensity from 1 to 10. RIR (Reps In Reserve) counts how many more reps you could have done. They are linked by the formula: RPE = 10 - RIR.
What RPE for building muscle?
For hypertrophy, aim for RPE 7-9 (RIR 1-3). This is the optimal zone according to scientific studies. You do not need to go to failure on every set.
Do I need to train to failure to make progress?
No! Studies (Pareja-Blanco 2020) show that stopping at RPE 8-9 (1-2 reps from failure) delivers as much or even more results than systematic failure, with less fatigue.
How do I know if I am really at RPE 8?
Do a few sets to failure to calibrate. Note the number of reps. Then you will know that at 2 reps from that number, you are at RPE 8. With practice, it becomes intuitive.
👨💼 About the author
Smart Rabbit - null