What is RPE?
RPE (Rate of Perceived Exertion) is a subjective measure of exercise intensity that represents your perceived effort during a workout. In simple terms, it's how "hard" you feel the exercise is. Unlike objective metrics such as heart rate or power, RPE reflects your overall experience—including muscle fatigue, breathing difficulty, and psychological feelings.
Why Does RPE Matter?
The key value of RPE lies in connecting "how you feel" with "the data." Research shows a strong correlation between perceived exertion and physiological stress (Borg, 1998). For endurance sports, RPE helps you gauge whether your current training intensity is within the target range, even without a heart rate strap or power meter.
Additionally, RPE helps identify "hidden fatigue." Sometimes your body is near its limits, but your heart rate may not fully reflect this yet. In such cases, RPE provides an extra reference point to help you avoid overtraining.
RPE Rating Scale
RPE uses a 1–10 scale, where higher numbers indicate greater fatigue:
| RPE | Description |
|---|---|
| 1 | Almost Effortless |
| 2 | Extremely Light |
| 3 | Very Light |
| 4 | Light |
| 5 | Moderate |
| 6 | Tiring |
| 7 | Challenging |
| 8 | Hard |
| 9 | Very Hard |
| 10 | Extremely Hard |
When no user input or Apple Health data is available, PeakWatch automatically calculates RPE based on workout duration and average heart rate, ensuring every training record has a reference value.
RPE in PeakWatch
PeakWatch supports three sources for RPE data:
- Apple Health Read: PeakWatch can read RPE data recorded in Apple Health (requires authorization in Apple Health settings), seamlessly synchronizing with the Apple ecosystem
- Manual Entry: After a workout, you can manually input your perceived exertion in PeakWatch
- Auto-Calculation: When no user input or Apple Health data is available, PeakWatch estimates RPE based on workout duration and heart rate data
In the training record detail view, RPE appears below "Training Effort." If you've entered an RPE value or Apple Health contains relevant data, the system displays these values first; otherwise, it shows the auto-calculated result. The comment next to RPE automatically matches the corresponding description based on the value.
Data Sync and Editing
When PeakWatch initiates a workout, it automatically calculates RPE based on exercise data. You can modify the RPE value in the training record, and changes will sync to Apple Health. This means your RPE data can flow between different apps while maintaining consistency.
References
Borg, G. A. (1998). Psychophysical bases of perceived exertion. Medicine and Science in Sports and Exercise, 14(5), 377–381.
Disclaimer: This article is for health education purposes only and is not intended as medical diagnosis or treatment. Please consult a healthcare professional if you experience any discomfort.