Rate of Perceived Exertion (RPE): What It Is, How to Use It, and Why It Matters in Your Training

What is RPE in gym?

Rate of Perceived Exertion (RPE) is a subjective scale used in the gym to quantify the intensity of a set or exercise, helping individuals gauge how hard they are working based on their physical and psychological sensations.

Defining RPE: The Borg Scale and Beyond

The concept of RPE originated from the Borg Rating of Perceived Exertion Scale, developed by Swedish researcher Gunnar Borg in the 1960s. This original scale typically ranged from 6 to 20, with 6 being "no exertion at all" and 20 being "maximal exertion." It was designed to correlate with heart rate during cardiovascular exercise, where multiplying the RPE by 10 roughly estimated the heart rate.

In modern strength training and resistance exercise, the RPE concept has evolved into a more intuitive 0-10 scale, often directly linked to Reps in Reserve (RIR). This adaptation provides a practical and actionable tool for lifters and coaches to manage training intensity and volume.

The RPE Scale Explained (0-10)

The 0-10 RPE scale in the context of resistance training primarily measures how many repetitions you could have performed before reaching technical failure (the point where you can no longer complete a rep with good form). This is where the connection to Reps in Reserve (RIR) becomes crucial:

• RPE 10 (0 RIR): Maximal effort. You could not have completed another repetition with good form. You went to absolute technical failure.
• RPE 9 (1 RIR): Very hard. You had one more repetition left in the tank. You could have done one more rep, but it would have been a grind.
• RPE 8 (2 RIR): Hard. You had two more repetitions left in the tank. This is often a sweet spot for strength and hypertrophy training.
• RPE 7 (3 RIR): Moderate-hard. You had three more repetitions left. This is still challenging but leaves a good buffer.
• RPE 6 (4 RIR): Moderate. You had four or more repetitions left. This might be used for warm-ups, technique practice, or very light accessory work.
• RPE 1-5: Very light to light effort. Typically used for warm-ups, mobility, or active recovery where there's minimal exertion or fatigue.

Key Principle: The RPE you assign should reflect the difficulty of the entire set, not just the last repetition. It encompasses the cumulative fatigue and effort required to complete the prescribed reps.

Why Use RPE in Your Training?

Incorporating RPE into your training offers several significant advantages:

• Individualization and Auto-regulation: Your strength and energy levels can fluctuate daily due to factors like sleep, nutrition, stress, and recovery. RPE allows you to auto-regulate your training intensity, ensuring you're working hard enough on good days and backing off slightly on bad days, preventing overtraining or under-training.
• Enhanced Self-Awareness: Regularly assessing RPE helps you develop a deeper understanding of your body's capabilities and limitations. This kinesthetic awareness is invaluable for long-term training success.
• Progressive Overload Guidance: While traditional percentage-based training dictates fixed loads, RPE helps ensure that the effort remains consistent or progresses. If you're getting stronger, a given weight might feel easier (lower RPE), prompting you to increase the load to maintain the target RPE.
• Injury Prevention: By allowing for daily adjustments, RPE can help prevent pushing too hard when your body isn't ready, reducing the risk of injury and excessive fatigue.
• Adaptability for Varied Goals: Whether you're training for strength (often higher RPE), hypertrophy (mid-high RPE), or endurance (lower RPE), the scale provides a flexible framework to structure your workouts.

How to Implement RPE in Your Workouts

Implementing RPE effectively requires practice and honest self-assessment:

• Start with Familiar Exercises: Begin by applying RPE to compound movements you're proficient in, such as squats, deadlifts, and bench presses.
• Practice with Submaximal Loads: Don't immediately jump to RPE 9-10. Start with loads where you know you have plenty of reps left (e.g., RPE 6-7) to get a feel for the scale.
• Assess After the Set: Wait until you've completed the entire set to assign an RPE. Consider the effort of the first rep, the last rep, and the overall pace and fatigue.
• Combine with Reps in Reserve (RIR): For strength training, mentally linking RPE to RIR is often the most practical approach. If your program calls for "3 sets of 5 reps at RPE 8," aim to complete 5 reps, knowing you could have done two more.
• Log Your RPE: Keep a training log that includes the weight, reps, and the RPE you assigned for each working set. This helps you track your perceived effort over time and identify trends.
• Be Honest with Yourself: The biggest challenge with RPE is its subjectivity. Avoid "ego lifting" by accurately assessing your effort, even if it means using a lighter weight than planned on a given day.
• Adjust as Needed: If a set feels much harder or easier than the target RPE, adjust the weight for subsequent sets. This is the essence of auto-regulation.

RPE vs. Traditional Percentage-Based Training

Traditional training often relies on percentages of a one-repetition maximum (1RM) (e.g., "3 sets of 5 reps at 80% of 1RM"). Both methods have merits:

• Percentage-Based Training:
  • Pros: Provides a clear, objective starting point; easy to program for beginners; useful for peaking cycles where precision is key.
  • Cons: Doesn't account for daily fluctuations in strength; can lead to overtraining or under-training if 1RM isn't accurately updated.
• RPE-Based Training:
  • Pros: Highly adaptable and individualized; accounts for daily readiness; fosters greater self-awareness.
  • Cons: Subjective, requires practice to master; less precise for beginners who struggle to gauge effort accurately.

Many advanced lifters and coaches use a hybrid approach, programming a target weight or percentage and then using RPE as a feedback mechanism to make real-time adjustments. For example, a program might say "5 reps at 80% 1RM, target RPE 8." If 80% feels like RPE 9 on that day, you might reduce the weight slightly for the next set.

Potential Challenges and Considerations

While powerful, RPE isn't without its challenges:

• Learning Curve: Accurately assessing RPE takes time and practice. Beginners often overestimate or underestimate their effort.
• Exercise Specificity: An RPE 8 on a squat might feel different from an RPE 8 on a bicep curl due to the different muscle groups involved and systemic fatigue.
• Psychological Factors: Motivation, pain tolerance, and even the presence of a spotter can influence perceived exertion.
• Acute vs. Chronic Fatigue: RPE primarily reflects acute fatigue within a set. It's important to also consider overall training volume and chronic fatigue.

Conclusion: Empowering Your Training

RPE is a sophisticated yet accessible tool that empowers you to train smarter, not just harder. By integrating the Rate of Perceived Exertion into your gym routine, you gain a deeper understanding of your body's capabilities, learn to auto-regulate your intensity, and ultimately build a more sustainable, effective, and injury-resilient training practice. It transforms your workouts from rigid, pre-determined tasks into dynamic, responsive sessions tailored to your daily readiness.