There are many ways to measure your effort levels on a run: pace, heart rate and blood lactate levels are just a few. Rate of perceived exertion (RPE) is often overlooked by runners in favor of more data-driven approaches but it’s a valuable tool to gauge your effort level and control your pace for different types of runs during your training.
What is RPE?
RPE involves measuring how hard you’re working, typically based on a scale of 1-10, with 1 being no activity and 10 being an all-out sprint. It’s a great way to get in touch with your body and monitor your effort levels without relying on technology or getting too caught up in the numbers.
No two runs are the same, and every day your performance could be affected by a number of internal and external factors, including weather, what type of shoes you’re wearing, the terrain, your own fatigue levels, how well-fueled you are and even how motivated you are to train. The advantage of RPE is that it accounts for all of these factors. One day, you could be running at 5 minutes/kilometre and you might put yourself at a 5 on the RPE scale, while on another day the same pace could feel more like a six or seven.
RPE vs. HR
Heart rate (HR) training is a close cousin to RPE. There are a few similarities, namely that both account for the internal and external factors that could affect your body on a run. This is because in general, your heart rate tends to correspond quite nicely with RPE, with a few notable exceptions:
It may not work for new runners or de-conditioned runners. When you’re first starting out (or coming back after a long layoff) and you don’t have a high degree of running fitness, your heart rate will climb much higher and faster than a well-trained athlete. You might be running at what you feel is a five or six on the RPE scale, but your heart rate might be much higher, suggesting you’re running at a much higher intensity.
It may not be accurate in the heat. When it’s really hot outside (and especially when it’s humid), your heart rate will be much higher than in the cool weather, even if you’re running at an intensity that feels easy or moderate.
Cardiac drift could affect your heart rate data. It’s normal for your heart rate to naturally drift upward during a run, even if you maintain the same pace throughout the entire thing. It’s mostly caused by the natural rise in body temperature as you run, and can cause a heart rate increase of up to 10-20 beats per minute, even if your effort level stays the same.
The advantages of RPE
While there are many reasons to use heart rate or other metrics to measure your effort level, there are a number of advantages to using RPE:
You don’t need any gadgets. For the runner who prefers to go tech-free, RPE is great because it doesn’t require a watch, heart rate monitor or any other gadgets.
RPE accounts for other external factors. Your heart rate can be affected by sleep, stress, caffeine, warm temperatures and even some medications. RPE takes these factors into account, allowing you to push yourself to the right level within those specific circumstances.
It helps you listen to your body. One of the best weapons for any runner is understanding your own body and learning its signals, so you know when to push yourself harder and when to back off. This will help you avoid injuries and overtraining, which will ultimately improve your performance.
Disadvantages of RPE
RPE is a great way to measure effort and intensity for most runners, but there are a few disadvantages:
For sedentary people. If you’re just starting to run after being mostly sedentary, even a slow, short run is going to feel difficult. Once you’ve been running for a while and your fitness starts to improve, you’ll be able to use the scale more effectively.
It’s subjective. Without actual numbers, RPE is difficult to accurately measure, and some people will underestimate their effort while others may overestimate it.
The bottom line
RPE is an excellent tool for runners to measure their effort because it takes into account the internal and external factors that may affect your ability to perform. While many runners prefer to use a more data-driven approach to their training, RPE can help you bust out of a slump by teaching you to listen to your body so you know when to go hard and when to back off.