Autoregulation is a training method where you adjust weight, reps, and effort based on your performance and readiness that day, rather than fixed percentages.
Strength can fluctuate up to 15-20% depending on your sleep, stress, fatigue, and overall recovery.
Tools like RPE, RIR, and bar speed can be used to adjust your session and let you train at the right intensity. This improves consistency, safety, and long-term progress.
Key Points You Need To Know!
Autoregulation allows you to alter your training session based on how you feel
RIR measures Reps In Reserve and is ideal for hypertrophy
RPE measures Rate of Perceived Exertion and is common in strength training
Bar Speed is the only objective measurement and a powerful tool to gauge fatigue
What Is Autoregulation in Training?
Key Takeaway
Autoregulation is a system that allows your daily readiness to determine how hard you train. Instead of forcing a predetermined load, autoregulation adapts to your real-time performance. It lets you adjust your training depending on how you feel.
Autoregulation matters because:
Strength varies meaningfully day to day
Perceived effort reflects accumulated fatigue
Various methods can accurately determine your readiness
You can modify your training if needed.
This allows your training to “fit” the day rather than fighting against it. No more forcing heavy loads if you need a break.
RPE: Rate of Perceived Exertion
Key Takeaway
The modified version of RPE uses a 1–10 scale to rate how hard a set feels; 1 means virtually no effort is needed, while 10 refers to true maximum effort. RPE is closely related to reps in reserve (when using a moderate rep range), but instead of approximating how many more reps you can do, it approximates how difficult the set or rep feels (Zourdos et al., 2016).
A set ending with about two reps left equals RPE 8, while a maximal-effort set with zero reps left equals RPE 10. RPE adjusts weight based on how difficult the set actually is, not what the spreadsheet says.
Strength and Hypertrophy RPE Scale
RPE 6: Just starting to feel challenging but still easy ~4 reps left
RPE 7: Challenging but doable; ~3 reps left
RPE 8: Hard effort; ~2 reps left
RPE 9: Very hard effort; ~1 rep left
RPE 10: Maximal effort; 0 reps left
How To Use RPE
Main method: Set a target effort level.
3X5 @ RPE 7–8
Increase or decrease weight until the set matches the intended RPE
Other method: Use a weight and perform reps until a targeted effort level
3XRPE 8 with 185lbs
Perform reps with 185lbs until the intended RPE
Pros of RPE
No equipment needed
Works for all lifts
Closely matches actual performance and bar speed (Helms et al., 2017)
Accurate in experienced lifters
Cons of RPE
Requires practice to judge accurately
Can be influenced by adrenaline, stress, or mood
RIR: Reps In Reserve
Key Takeaway
RIR measures how many reps you have left before failure. Two reps in reserve (2 RIR) means you could have done two more reps with good form. RIR is intuitive and highly effective for hypertrophy, because effort near failure produces the strongest stimulus (Zourdos et al., 2016).
RPE ↔ RIR Conversion
4 RIR = RPE 6
3 RIR = RPE 7
2 RIR = RPE 8
1 RIR = RPE 9
0 RIR = RPE 10
RIR can be easier for trainees to judge compared to RPE.
How To Use RIR
Hypertrophy: Generally uses lower RIR (1-3RIR), where most growth occurs (Zourdos et al., 2016).
Strength: Generally uses 1-2 RIR to maintain quality
Increase RIR on days of high fatigue or want less intensity
Decrease RIR when feeling strong or wanting higher intensity
Adjust RIR mid-set if bar speed suddenly slows (Helms et al., 2017)
Pros of RIR
Beginner-friendly
Easier for many to judge
Clear proximity-to-failure measure
Highly effective for muscle growth (Refalo et. al, 2024)
Cons of RIR
Subjective
Less efficient with low-rep strength work
Intensity can vary depending on number of reps, especially extreme ends (3RIR feels very different using 4RM and 20RM)
Bar Speed (Velocity-Based Training)
Key Takeaway
Bar speed measures how fast the barbell moves during a rep. Fast reps indicate readiness; slow reps indicate fatigue. As you measure the bar speed, it is the most objective form of autoregulation because it measures actual neuromuscular performance, not perception.
You can use it to:
Measure the load by bar speed
Fatigue accumulation and RPE by comparing the speed of the first rep.
Tip: Bar speed is first noticeable when a trainee hits a 6-7RPE. In addition, a significant drop in speed from the first rep indicates an 8RPE. This can be used to easily identify this intensity.
Why Bar Speed Works
Accurately predicts percentage of 1RM (González-Badillo & Sánchez-Medina, 2010).
Predicts RPE accurately (Helms et al., 2017).
Velocity loss shows fatigue accumulation (Pareja-Blanco et al., 2017, 2020).
Strongly correlates with reps left and training adaptations (Pareja-Blanco et al., 2017).
Use the graph below for more specific velocity loss dependent on goals
Training Goal
Approximate Bar Speed (Concentric)
Percentage of 1RM
Recommended Velocity Loss per Set
Max Strength
0.1-0.5m/s
85%+
~10-20%
Power
0.75-1.3m/s+
40-70%
Low (focus on quality)
Hypertrophy
Wide Range (typically 0.5-1.0m/s with moderate loads)
60-80%
~40-50% (training close to failure)
How To Use Bar Speed With a Device
Track typical first-rep velocity for each lift (González-Badillo & Sánchez-Medina, 2010)
Reduce load 2.5–5% if the first rep is slower than usual
Use velocity thresholds (e.g., 0.20–0.25 m/s for strength work).
Stop sets at 20–25% velocity loss to balance progress and fatigue (Pareja-Blanco et al., 2017, 2020).
How To Use Bar Speed Without a Device
Watch for visible rep slowdown
Record sets and compare rep one with later reps
Use a simple first-rep speed scale (1–5)
If the bar moves slowly despite high intent, reduce load
Use graph below for basic recommendations on training goals
May take time to learn how to spot reductions, but becomes easy with experience
Pros of Bar Speed
Most objective autoregulation method
Very easy to use for general use once learned
Excellent for strength and power
Detects fatigue earlier than RPE (Pareja-Blanco et al., 2017)
Cons of Bar Speed
Devices cost money
Visual estimation requires practice
How RPE, RIR, and Bar Speed Work Together
RPE
RIR (Reps in Reserve)
Bar Speed (m/s)
Description
6
4
1.0-1.3m/s
First sign of effort, but easy. About four reps left.
7
3
0.75-1.0m/s
Moderate effort. Three reps left. Slight slowdown.
8
2
0.50 – 0.75 m/s
Hard effort. Two reps left. Significant slowdown.
9
1
0.30-0.50m/s
Very hard. One rep left. Last rep is a grind, but still moving.
10
0
<0.30m/s
Maximal effort. No reps left. Bar may slow to a near stop.
Key Takeaway
RPE, RIR, and bar speed all measure readiness and fatigue from different angles. RPE and RIR describe perceived difficulty, while bar speed provides objective data. Using all three together gives a complete picture of performance for accurate load selection.
RPE correlates with velocity correlation (Helms et al., 2017)
RIR and RPE (Zourdos et al., 2016)
Velocity loss indicates fatigue prediction (Pareja-Blanco et al., 2017)
Practical Ways to Combine These Tools
RIR is generally ideal for hypertrophy (0–3 RIR).
RPE is more suitable for strength (RPE 7–9) due to low reps.
Use bar speed for compound lifts and complementary measurement
Use the agreement rule: RPE, RIR, and bar speed must agree.
Use video to track bar speed without devices.
Summary
Above are 3 effective and useful forms of autoregulation. They’re all effective yet offer slightly greater benefits for various situations and purposes.
RPE measures subjective effort and is useful in strength training
RIR measures reps left before failure and is ideal for hypertrophy.
Bar Speed measures objective performance and fatigue. Can be used for any situation, independent or in unison with RIR or RPE.
Together, they form a comprehensive autoregulation system that adapts training to daily readiness, improves safety, enhances hypertrophy and strength, and increases long-term progress.
People Also Ask
What is the best autoregulation method for strength training?
Bar speed is the most objective, while RPE is ideal for subjective. Look for a noticeable drop in bar speed, which indicates RPE 8.
How close to failure should I train for muscle growth?
Most hypertrophy occurs at 0–3 RIR (Refalo et. al, 2024)
Is bar speed necessary for beginners?
No. Beginners can start with RPE or RIR and add bar-speed tools later.
How do I know when to increase weight?
Increase weight when RPE is lower than targeted, RIR is higher than expected, and bar speed is faster than normal.
Should I train to failure?
Occasional failure is fine. For most growth and recovery, use 0–3 RIR.
Can I autoregulate without equipment?
Yes. Use RPE, RIR, and visible bar-speed changes.
Quick Definitions For AutoRegulation
What is RPE?
RPE (Rate of Perceived Exertion) is a 1–10 scale measuring set difficulty based on effort and fatigue.
What is RIR?
RIR (Reps In Reserve) is the number of reps left before failure at the end of a set.
What is bar speed?
Bar speed measures how fast a barbell moves. This is correlated to intensity and accumulation of fatigue.
References
Helms, E. R., Storey, A., Cross, M. R., Brown, S. R., Lenetsky, S., Ramsay, H., & Dillen, L. F. (2017). RPE and velocity relationships for the back squat, bench press, and deadlift in powerlifters. Journal of Strength and Conditioning Research, 31(2), 472–481. https://doi.org/10.1519/JSC.0000000000001517
González-Badillo, J. J., & Sánchez-Medina, L. (2010). Movement velocity as a measure of loading intensity in resistance training. International Journal of Sports Medicine, 31(5), 347–352. https://doi.org/10.1055/s-0030-1248333
Pareja-Blanco, F., Rodríguez-Rosell, D., Sánchez-Medina, L., González-Badillo, J. J., & Mora-Custodio, R. (2017). Effect of velocity loss during resistance training on athletic performance, strength gains, and muscle adaptations. Scandinavian Journal of Medicine & Science in Sports, 27(7), 724–735. https://doi.org/10.1111/sms.12678
Pareja-Blanco, F., Rodríguez-Rosell, D., Aagaard, P., & González-Badillo, J. J. (2020). Velocity loss as a critical variable determining adaptations to strength training. Medicine & Science in Sports & Exercise, 52(7), 1752–1762. https://doi.org/10.1249/MSS.0000000000002295
Refalo, M. C., Helms, E. R., Robinson, Z. P., Hamilton, D. L., & Fyfe, J. J. (2024). Similar muscle hypertrophy following eight weeks of resistance training to momentary muscular failure or with repetitions-in-reserve in resistance-trained individuals. Journal of Sports Sciences, 42(1), 85–101. https://doi.org/10.1080/02640414.2024.2321021
Zourdos, M. C., Klemp, A., Dolan, C., Quiles, J. M., Souza, E. O., Blanco, R., Krahmer, R., Orange, S. T., Hoffman, J. R., & Kell, R. T. (2016). Novel resistance training–specific rating of perceived exertion scale measuring repetitions in reserve. Journal of Strength and Conditioning Research, 30(1), 267–275. https://doi.org/10.1519/JSC.0000000000001049
