Your Guide to RPE and RIR: The Secret to 'Auto-Regulating' Your Training
In a perfect world, every time you walk into the gym, you feel strong, energized, and ready to hit your target numbers. But in the real world of busy professionals, life gets in the way. A poor night's sleep, a high-stress day at work, or residual fatigue from a previous session can all impact your performance.
So, what do you do when your percentage based training program says "5 sets of 5 at 85% of your one-rep max," but your body is telling you it's not going to happen? Do you push through and risk injury, or go too light and waste a session?
This is where the concept of Auto-Regulation comes in. Championed by leaders in exercise science and reactive training systems, it's the practice of adjusting your training load based on how you feel on a specific day. The two most powerful tools for this are RPE (Rate of Perceived Exertion) and RIR (Reps in Reserve).
Mastering these concepts is the difference between blindly following a program and intelligently managing it to maximize performance.
RPE and RIR are advanced tools used to manage your training intensity within a structured plan. To understand the bigger picture of how to organize your training block, we highly recommend reading our foundational guide: What is Periodization? The Secret to Long-Term Muscle Gain.
What is RPE (Rate of Perceived Exertion)?
RPE is a subjective scale from 1 to 10 used to measure your perceived effort during a set. Instead of asking "how much weight did I lift?", it asks "how hard did that feel?"
The RPE Scale for Strength Training:
RPE 10: Maximum effort. You could not have done another rep. This is true muscular failure.
RPE 9: Very hard effort. You were confident you could have done one more rep, but no more (1 Rep in Reserve).
RPE 8: Hard effort. You had two more good reps left in the tank (2 Reps in Reserve).
RPE 7: Moderate effort. You had three more good reps left (3 Reps in Reserve).
RPE 1-6: From very light effort to moderate. These are typically used for warm ups or recovery work.
What is RIR (Reps in Reserve)?
RIR is the inverse of RPE and is often easier to grasp. It simply asks, "how many more reps could I have done with proper form?" This is the foundation of the RIR based RPE scale.
The RIR Scale (as it relates to RPE):
0 RIR: No reps in reserve. (Same as RPE 10)
1 RIR: One rep in reserve. (Same as RPE 9)
2 RIR: Two reps in reserve. (Same as RPE 8)
3 RIR: Three reps in reserve. (Same as RPE 7)
A coach might prescribe "3 sets of 5 reps at an RPE 8" or, identically, "3 sets of 5 reps with 2 RIR." Both mean the same thing: choose a weight that allows you to complete 5 reps performed, but you feel like you could have done 7 if you had to.
Why Auto-Regulation is a Superior Way to Train
For advanced athletes and physique competitors, using RPE/RIR is more intelligent and adaptable than rigid percentage based training.
It Accounts for Daily Fluctuations: A percentage based program doesn't care if you had a bad night's sleep. RPE/RIR does. On low energy days, your "RPE 8" weight might be lower, but the training stress on your nervous system is the same. This ensures you're always training in the optimal zone with less fatigue.
It Promotes Better Form and Reduces Injury Risk: The RPE/RIR scale is based on reps with proper form. It teaches you to be honest. If your form breaks down, the set is over. This focus on quality is crucial for injury prevention.
It's the Perfect Alternative to Hitting Failure: The vast majority of your resistance training should be done in the RPE 7-9 (or 1-3 RIR) range. This provides nearly all of the muscle growth stimulus with a fraction of the systemic fatigue.
This doesn't mean hitting failure is always bad. It's an advanced tool with specific uses. Learn more in our Guide to Training to Failure.
Practical Application: RPE/RIR in a Training Block
Using RPE/RIR is a skill that has a learning curve, but it becomes intuitive within a few weeks.
Focus on Main Lifts: Use it for your heavy compound lifts like the bench press or overhead press to guide your weight selection for the day.
Guide Progression: A periodized training block can use RPE to ensure progressive overload. For example, on your dumbbell bench press:
Week 1: 3 sets of 8 reps @ RPE 7
Week 2: 3 sets of 8 reps @ RPE 8 (You'll naturally have to increase weight to make it harder)
Week 3: 3 sets of 8 reps @ RPE 9
Week 4: Deload
Use it for Accessory Work: For isolation work like bicep curls, you might push closer to failure (RPE 9-10), while for heavy compound lifts, you stay further away (RPE 7-8).
Conclusion: Listen to Your Body, Guide Your Progress
Auto-regulation using RPE and RIR is the hallmark of an advanced, intelligent athlete. It moves you from being a passive follower of a program to an active participant in your own training. By learning to listen to your body and auto-regulate intensity, you can manage fatigue, ensure every session is productive, and build a truly resilient and powerful physique.
Ready to Train Smarter, Not Just Harder?
Understanding these concepts is the first step. The next is having an expert coach design a program that uses them effectively. Let us build a personalized, auto-regulated training plan that adapts to your life and guarantees you get the best possible results.
