Rate of Perceived Exertion (RPE): Meaning, Scales, Benefits, and Application

What is the Meaning of RPE?

The Rate of Perceived Exertion (RPE) is a subjective scale used in exercise science to quantify the intensity of physical activity, reflecting how hard an individual feels they are working during an exercise or workout.

Understanding the RPE Scale

The concept of RPE was initially popularized by Swedish researcher Gunnar Borg in the 1970s, leading to the development of the Borg RPE Scale. This original scale ranged from 6 to 20, where 6 represented no exertion at all and 20 represented maximal exertion. The numbers were chosen to roughly correlate with heart rate (e.g., RPE 12-13 correlating to approximately 120-130 beats per minute).

However, in modern fitness and strength training, a modified RPE Scale (0-10) is more commonly used due to its simpler and more intuitive nature:

• 0: Nothing at all (e.g., sitting on a couch)
• 1: Very, very light activity (e.g., walking slowly)
• 2: Very light activity
• 3: Moderate activity (e.g., brisk walk, able to hold a conversation easily)
• 4: Somewhat hard activity
• 5: Hard activity (e.g., feeling breathless but can still speak in short sentences)
• 6: Hard activity
• 7: Very hard activity (e.g., struggling to speak more than a word or two)
• 8: Very, very hard activity
• 9: Extremely hard activity (e.g., maximal effort, cannot speak)
• 10: Maximal effort (e.g., an all-out sprint or a 1-rep max lift)

When applying RPE to resistance training, it often correlates with Reps in Reserve (RIR), where an RPE of 8 might mean you had 2 repetitions left in the tank before reaching muscular failure.

Why Use RPE in Training?

Incorporating RPE into your training provides several significant benefits, moving beyond rigid percentages to a more adaptive and individualized approach.

• Autoregulation: RPE allows you to adjust your training intensity based on your daily readiness. Factors like sleep quality, stress levels, nutrition, and recovery status can significantly impact performance. On a day when you feel fatigued, an RPE 7 might be achieved with less weight than usual, preventing overtraining and burnout. Conversely, on a day you feel strong, you might lift more while maintaining the target RPE.
• Individualization: Training programs often prescribe percentages of a one-repetition maximum (1RM). However, 1RM can fluctuate daily, and these percentages don't account for individual differences in work capacity or fatigue. RPE provides a personalized measure of effort, ensuring the intended stimulus is met for each individual.
• Progression and Periodization: RPE helps manage training load over time. By targeting specific RPEs for different training phases (e.g., higher RPEs during intensity blocks, lower RPEs during deloads), coaches and athletes can systematically progress and recover.
• Safety and Injury Prevention: By listening to your body's signals through RPE, you can avoid pushing too hard on days when your body isn't ready, reducing the risk of injury and overtraining syndrome.
• Accessibility: RPE is a free, immediate, and universally applicable tool that requires no special equipment. It empowers individuals to take a more active role in monitoring their own training.
• Developing Body Awareness: Consistently using RPE helps athletes and exercisers develop a deeper understanding of their own body's signals, improving their ability to gauge effort and fatigue.

How to Accurately Apply RPE

Accurately applying RPE requires practice and self-awareness.

• Listen to Your Body: Focus on internal cues such as breathing rate, muscle fatigue, and overall feeling of effort. It's not just about how heavy the weight feels, but how hard your body is working to move it.
• Practice and Consistency: Like any skill, accurately gauging RPE improves with consistent practice. Log your RPE after each set or exercise and compare it to your actual performance (e.g., reps achieved, weight lifted). Over time, you'll become more adept at predicting your RPE.
• Consider All Factors: Before assigning an RPE, take into account your sleep, stress, nutrition, and previous training sessions. These factors significantly influence your perceived effort.
• Use it with Other Variables: While powerful, RPE should not be the sole determinant of your training. Combine it with other programming variables such as sets, repetitions, and load to create a comprehensive training plan.
• Be Honest with Yourself: The biggest challenge with RPE is the inherent subjectivity. Be honest about your effort level, avoiding the temptation to underestimate or overestimate.

Practical Application: RPE in Different Training Styles

RPE can be effectively integrated into various forms of exercise.

Strength Training

For resistance training, RPE is often used to prescribe the intensity of a set, particularly in relation to muscular failure.

• Warm-ups: Often performed at RPE 5-6 (easy, few reps in reserve).
• Hypertrophy Training (Muscle Growth): Typically targets RPE 7-9 (1-3 reps in reserve), ensuring sufficient stimulus for muscle adaptation without always going to absolute failure.
• Strength Training (Powerlifting): Can involve higher RPEs, such as RPE 8-9 for working sets, and RPE 9-10 for top sets or competition lifts, reflecting a high level of effort close to maximal.
• Deloads/Recovery: Lower RPEs (e.g., RPE 6-7) are used to reduce training stress while maintaining movement patterns.

Cardiovascular Training

RPE is excellent for monitoring aerobic and anaerobic conditioning.

• Low-Intensity Steady-State (LISS) Cardio: Aim for RPE 2-4 (easy, conversational pace).
• Moderate-Intensity Cardio: Target RPE 5-6 (can speak in short sentences, breathing heavily).
• High-Intensity Interval Training (HIIT): Work intervals typically aim for RPE 8-10 (maximal or near-maximal effort, difficult to speak), followed by recovery intervals at RPE 2-4.

Limitations and Considerations

While RPE is a powerful tool, it's important to acknowledge its limitations:

• Subjectivity: The primary limitation is its subjective nature. Two individuals performing the same exercise at the same absolute intensity might report different RPEs. Even for the same individual, RPE can vary daily.
• Learning Curve: Beginners may struggle to accurately gauge their RPE initially, often underestimating or overestimating their effort.
• Influence of External Factors: While RPE accounts for these, extreme emotional states, pain, or significant distractions can distort perceived effort.
• Not a Replacement for Objective Measures: While valuable, RPE should complement, not entirely replace, objective measures like load, reps, time, or heart rate, especially in clinical or research settings.

Conclusion

The Rate of Perceived Exertion (RPE) is an invaluable, evidence-based tool for anyone serious about optimizing their training. By providing a flexible, individualized, and autoregulated approach to intensity, RPE empowers athletes, fitness enthusiasts, and coaches to make informed decisions about daily training loads, promote consistent progress, and safeguard against overtraining. Mastering RPE isn't just about assigning a number; it's about developing a deeper connection with your body's signals, leading to more intelligent and sustainable training.