RPE vs RIR vs Percentage-Based Training: The 2025 Science of Auto-Regulation

If you've been lifting for any length of time, you've probably encountered the debate: should you train using fixed percentages of your one-rep max, or should you listen to your body and adjust on the fly?

The fitness industry has been buzzing about auto-regulation for years now, with advocates claiming it leads to better strength gains, fewer plateaus, and less burnout. Skeptics argue it's too subjective and inconsistent.

A groundbreaking 2025 network meta-analysis just settled some of these debates—and the results might surprise you.

What Is Auto-Regulation, Anyway?

Before diving into the data, let's clarify the different approaches:

Percentage-Based Resistance Training (PBRT)

This is the traditional approach: you calculate your 1RM, then train at a fixed percentage (e.g., 80% of your 1RM for 5 sets of 5). The load stays constant unless you retest your max.

Pros: Simple, predictable, easy to program Cons: Doesn't account for daily fatigue, life stress, or recovery

Rating of Perceived Exertion (RPE)

With RPE, you rate how hard a set felt on a 1-10 scale. An RPE 8 means you had 2 reps left in the tank. This lets you adjust load based on how you're feeling that day.

Repetitions in Reserve (RIR)

RIR is closely related to RPE—it simply inverts the scale. RIR 0 = training to failure, RIR 2 = you could've done 2 more reps. Many lifters find this more intuitive than RPE.

Velocity-Based Training (VBRT)

VBRT uses a device (like a linear encoder) to measure bar speed. As you fatigue, bar speed decreases. When it drops below a certain threshold, you stop the set.

Autoregulating Progressive Resistance Exercise (APRE)

APRE, developed by Matt Brzycki, uses your actual performance to determine load. You do a set at a given weight, and based on how many reps you complete, you adjust the weight for the next set.

The 2025 Meta-Analysis: What the Science Says

Researchers conducted a network meta-analysis—a sophisticated method that compares multiple interventions simultaneously—to determine which auto-regulation method works best for maximal strength.

The study examined 1RM improvements in the back squat and bench press across numerous randomized controlled trials.

Key Findings

For Back Squat 1RM:

• APRE: 93.0% (most optimal)
• RPE: 66.8%
• VBRT: 27.0%
• PBRT: 13.2% (least effective)

For Bench Press 1RM:

• APRE: 97.1% (most optimal)
• VBRT: 57.1%
• RPE: 29.9%
• PBRT: 15.9% (least effective)

The conclusion was clear: APRE, VBRT, and RPE were all significantly more effective than traditional percentage-based training for building maximal strength.

Why Does Auto-Regulation Win?

1. Daily Fluctuations Are Real

Your body doesn't operate in a vacuum. Sleep quality, stress levels, hydration, menstrual cycles (for women), and countless other factors affect your performance from day to day.

A 2023 study in the Journal of Strength and Conditioning Research found that daily strength can vary by 5-15% depending on these factors. When you lock in a fixed percentage, you're essentially ignoring this reality.

2. Optimal Fatigue Management

Traditional percentage-based programs assume linear progress. But your body has good days and bad days. Auto-regulation lets you:

• Push harder on good days (when you feel fresh)
• Back off on bad days (preventing overtraining)
• Match intensity to recovery (optimizing gains)

3. Reduced Injury Risk

When you're feeling fatigued but still hitting a prescribed percentage, you're more likely to compromise form. Auto-regulation lets you bail out of a set before your technique breaks down.

Practical Application: Which Method Should You Use?

Based on the 2025 evidence, here's how to choose:

If You're Focused on Maximal Strength (Powerlifting)

APRE showed the highest probability of success. The method naturally adjusts load based on daily performance, making it ideal for strength development. How to implement: Start with a weight you can do for 10 reps. Based on reps completed:

• 10+ reps: Increase weight by 10%
• 8-9 reps: Increase by 5%
• 6-7 reps: Keep weight the same
• <6 reps: Decrease by 5%

If You Want Simplicity + Effectiveness

RPE/RIR is your best bet. It's backed by solid research and easy to implement without any equipment. How to implement: For hypertrophy, train at RPE 7-8 (2-3 RIR). For strength, push to RPE 8-9 (1-2 RIR). For strength-endurance, go to RPE 9-10 (0-1 RIR).

If You Have Access to Technology

VBRT showed strong results, especially for bench press. If you train at a facility with linear encoders or velocity tracking apps, this is a viable option.

If You Love Your Percentage Program

That's fine—just recognize its limitations. Consider deloading when you feel off, and don't be afraid to adjust based on RPE even within a percentage-based framework.

The Bottom Line

The 2025 meta-analysis is unambiguous: auto-regulation methods outperform traditional percentage-based training for building maximal strength.

APRE took the top spot, but RPE/RIR remains the most accessible and practical method for most lifters. The key insight isn't which specific method you choose—it's that adapting your training to daily readiness beats rigid programming.

Your body is constantly sending you signals. Learning to listen to them isn't just smart—it's scientifically proven to get you stronger.

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References

• Zhang et al. (2025). "Autoregulated resistance training for maximal strength enhancement: A systematic review and network meta-analysis." Journal of Functional Anthropology. Published February 2025.

• Weakley et al. (2023). "The efficacy of velocity-based training for strength and power development." Sports Medicine.

• Helms et al. (2022). "RPE vs. RIR: The complete guide." MASS Research Review.

• Brzycki, M. (1998). "A practical approach to strength training." McGraw-Hill.