How to Use RPE and RIR in Training

RPE vs RIR: Quick Refresher

Before diving into application, let's clarify the two scales. RPE (Rate of Perceived Exertion) runs from 1-10, where 10 means maximum effort (failure). RIR (Reps in Reserve) counts how many more reps you could do: RIR 2 means you had 2 reps left in the tank.

The relationship is simple: RPE = 10 - RIR. So RIR 2 equals RPE 8, and RIR 0 equals RPE 10 (failure). Most modern programs use RIR because it's more intuitive for lifters to think "how many more could I do?" rather than rating effort on a scale.

For a detailed breakdown of the scales and conversion chart, see our RPE/RIR Calculator or the glossary definitions.

When to Use RPE/RIR vs Percentages

The choice between autoregulation (RPE/RIR) and percentage-based training depends on your goals, training phase, and individual factors:

Use Percentage-Based Training When:

• Peaking for competition: You need precise loads for competition prep where predictability matters more than daily optimization.
• Following a specific program: Programs like 5/3/1 or Starting Strength are designed around percentages.
• You're a beginner: Beginners often lack the body awareness to estimate RIR accurately. Fixed weights teach form and build foundation.
• Main strength lifts: Heavy singles, doubles, and triples where small load differences significantly impact performance.

Use RPE/RIR When:

• Hypertrophy training: Where total volume and proximity to failure matter more than exact weights.
• Your recovery varies: Sleep, stress, nutrition fluctuate. RPE accounts for daily readiness automatically.
• Accessory and isolation work: Where psychological effort varies and precise percentages don't apply.
• Long-term development: RPE prevents both undertraining on good days and overreaching on bad days.

How to Calibrate Your RIR

Accurate RIR estimation is a skill that improves with practice. Here's how to develop it:

Step 1: Establish Baselines (Week 1-2)

Start by occasionally taking sets to true failure (safely, on machines or with a spotter). This teaches you what RIR 0 actually feels like. Most lifters overestimate their RIR by 2-3 reps initially.

Step 2: Identify Your Signals (Week 2-4)

Pay attention to the physical cues at different RIR levels:

• RIR 4+: Bar speed is fast, breathing easy, minimal muscle burn.
• RIR 3: Bar starts to slow, you feel the working muscles clearly.
• RIR 2: Bar speed notably slower, significant effort, breathing harder.
• RIR 1: Grinding, form starting to shift, you're fighting for each rep.
• RIR 0: The next rep would fail. You couldn't do one more even with a gun to your head.

Step 3: Use AMRAP Sets for Calibration

Program occasional AMRAP (As Many Reps As Possible) sets. Predict your reps beforehand, then see how accurate you were. If you predicted 8 reps and got 11, your RIR perception is off.

Step 4: Video Review

Film your sets occasionally. Bar speed is the most objective indicator of proximity to failure. Compare your perceived RIR to actual bar speed on the last few reps.

Daily Application: Choosing Target RIR

Different exercises and training phases call for different RIR targets:

By Exercise Type

By Mesocycle Phase

• Accumulation (weeks 1-2): RIR 3-4. Building volume, staying fresh.
• Intensification (weeks 3-4): RIR 2-3. Pushing harder as you adapt.
• Peak/Overreach (week 5): RIR 1-2. Highest stimulus before deload.
• Deload (week 6): RIR 4-5. Active recovery, light loads.

Adjusting for Daily Readiness

Your target RIR stays the same, but the weight you use to hit that RIR changes based on how you feel:

• Great day: Same RIR target, but you'll need more weight to hit it.
• Bad day: Same RIR target, less weight needed. You're still training appropriately for your readiness.

This is the magic of autoregulation—you automatically adjust load to match daily capacity while maintaining appropriate relative intensity.

Common Mistakes with RPE/RIR

1. Sandbagging (Underestimating Capacity)

The most common error. You say "RIR 2" but actually had 4-5 reps left. Signs: you never fail sets, your RIR estimates never change, you're not progressing.

Fix: Occasionally test to failure on safe exercises. Compare predicted vs actual reps.

2. Ego Lifting (Overestimating Capacity)

Claiming "RIR 2" when you were actually at failure. Form breaks down, you fail sets unexpectedly, injuries creep up.

Fix: Video your sets. Be honest about bar speed and form breakdown.

3. Inconsistent Standards

RIR 2 means different things on different days depending on your mood. This defeats the purpose of autoregulation.

Fix: Define what each RIR level feels like for you. Use objective markers (bar speed, breathing) not just feelings.

4. Ignoring Context

Using the same RIR for all exercises regardless of type, rep range, or fatigue state.

Fix: Adjust RIR targets by exercise (see tables above). Account for accumulated fatigue within a session.

5. Not Tracking

Using RPE/RIR without recording it. You can't identify patterns or progress without data.

Fix: Log RIR for every set. Review weekly to spot trends.

Tracking RIR Over Time

RIR data becomes powerful when tracked consistently. Here's what to look for:

Signs of Progress

• Same RIR with more weight over weeks
• Same weight with lower RIR (it feels easier)
• Consistent RIR estimates (calibration is improving)

Warning Signs

• RIR increasing despite not changing weight (fatigue accumulation)
• Same weight feels harder every session (recovery issues)
• RIR estimates wildly inconsistent (need recalibration)

Pattern Recognition

Track long enough and you'll notice patterns: certain exercises you always underestimate, specific days of the week you're fresher, how caffeine or sleep affects your capacity. This self-knowledge is invaluable for programming.

How Arvo Automates This

Manual RPE/RIR tracking requires discipline and self-awareness. Arvo handles this automatically:

• Real-time RIR tracking: Log your RIR after each set, and Arvo immediately adjusts your next set's target weight.
• Historical analysis: Arvo compares today's performance to your history, detecting if you're sandbagging or genuinely fatigued.
• Pattern detection: The AI learns your RIR calibration over time, accounting for your personal perception tendencies.
• Methodology integration: Different training methods use RIR differently. Kuba Method targets RIR 1-3, Mentzer HIT goes to RIR 0. Arvo applies the right standards automatically.
• Transparent reasoning: Unlike black-box apps, Arvo shows you exactly why it's suggesting a weight change based on your RIR reports.

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