What RPE Measures During Exercise

If you’ve ever wondered whether you’re working out hard enough or maybe too hard the Rate of Perceived Exertion (RPE) scale can help. This simple tool doesn’t require any equipment and offers real-time insight into how your body feels during exercise. Whether you’re training for a race, lifting weights, or recovering from injury, RPE can help you tune into your body and train more effectively.

What Is the Rate of Perceived Exertion (RPE)?

The RPE scale measures how hard you feel like you're working during physical activity. It’s based on your own perception of effort, not on external metrics like heart rate or speed. The most commonly used version ranges from 0 to 10:

• 0: Resting, sitting still

• 1: Very light effort

• 2–3: Light activity (easy walk, light yoga)

• 4–5: Moderate exercise (breathing and heart rate increased, but still manageable)

• 6–7: Vigorous exercise (you can speak a few words, but conversation is difficult)

• 8–9: Very intense (breathing heavily, can’t speak)

• 10: Maximum effort (sprinting or lifting at your absolute limit)

Why Use the RPE Scale in Your Workouts?

The RPE scale can be used with almost any type of exercise running, cycling, weightlifting, HIIT, or even physical therapy. Here’s why it matters:

• It helps you gauge effort accurately. You don’t need a smartwatch or fitness tracker to know how hard you’re working.

• It adapts to your daily condition. Feeling under the weather? You might reach an RPE of 7 faster than usual. Well-rested? That same workout may only feel like a 4.

• It supports balanced training. Use it to push hard when needed (e.g., during intervals) and back off during recovery sessions.

According to the CDC, adults should aim for at least 150 minutes of moderate-intensity activity per week. Using the RPE scale makes it easier to stay on track even without tracking devices.

Who Benefits Most From Using RPE?

Anyone can benefit from understanding their RPE, but it’s especially helpful for:

• HIIT practitioners: The scale helps you push during the high-intensity bursts and fully recover during the rest intervals.

• Weightlifters: RPE can guide your sets and help you understand when to increase weight or adjust reps.

• People recovering from injury: RPE keeps the focus on current effort, not past performance allowing you to challenge yourself safely during rehab.

The Borg Scale: An Older Version of RPE

Before the modern 0–10 scale, Swedish researcher Gunnar Borg developed a scale ranging from 6 to 20, which was loosely correlated with heart rate (multiply the number by 10 to estimate beats per minute). While less intuitive, it's still used in some medical and rehabilitation settings.

Borg RPE chart highlights:

• 6–9: Very light effort

• 10–12: Light to moderate

• 13–16: Moderately hard to hard

• 17–20: Very hard to maximum effort

How to Use RPE During Exercise

The beauty of RPE is its flexibility. After a set or interval, take a moment to assess: How hard did that feel on a scale from 0 to 10? Over time, this becomes second nature and helps you:

• Recognize when to push or rest

• Avoid overtraining or injury

• Make steady progress toward fitness goals

Example: You usually lift 100 pounds for five reps at an RPE of 6. One day, it feels like an 8 your body may be telling you to scale back or take an extra rest day.

Is RPE Accurate?

Yes despite being subjective, studies show RPE aligns well with objective measures like heart rate and VO₂ max. Research published in the Journal of Strength and Conditioning Research found that RPE rises predictably with exercise intensity, even across different age groups and fitness levels.

Medical and Rehab Applications

RPE is a staple in many physical therapy programs. It's especially useful in settings where heart rate monitoring isn't ideal or possible. It provides feedback to therapists and patients about whether the workload is appropriate for recovery and rebuilding strength.

How RPE Compares to Heart Rate Monitoring

While RPE isn't a replacement for heart rate tracking, it complements it well. Tools like fitness watches provide data, but they don't always account for how you feel. The "talk test" is another informal method: if you can talk but not sing, you're likely in a moderate-intensity zone (RPE 4–5); if speaking is hard, you’re likely pushing toward an RPE of 7 or above.

Bottom Line

The RPE scale is a simple, effective tool to measure workout intensity based on how your body feels. It can help you stay in tune with your energy levels, prevent injury, and ensure you're meeting your training goals whether you're a beginner or a seasoned athlete.

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