RPE: Why Ignoring Your Power Meter Can Make You Faster

Power measurement has become an important tool for establishing training zones, effectively pacing efforts, and tracking overall training loads. As smart trainers and power meters become more affordable, more athletes than ever before are using power-based performance data to help them get the most out of their training. The unintended consequence, however, is that many athletes have become too reliant on their power numbers. Many have lost the ability to simply listen to their bodies and focus on the sensations of a given effort. But what if we told you there was a secret training tool that is available free to anyone and everyone who knows how to use it? Too good to be true?

Long Time No See, RPE

RPE, also known as “Recommended Perceived Exertion” or “Rate of Perceived Exertion” is a subjective scale of how an effort feels. No matter how many gadgets and metrics you use to monitor a workout, you still need to be able to assess those numbers in the context how much (or little) pain you’re feeling.

RPE uses a simple “0-10” scale, with “0” akin to lying on the floor sleeping and “10” being an all out, eye-bleeding, maximal effort. Every effort in a Sufferfest workout has Power, Cadence, Heart Rate and RPE targets associated with it. By combining the information from these four metrics you should get a very clear picture of the intended effort of each interval. Some people tend to focus only on Power or Cadence, while others may focus primarily on Heart Rate. Regardless of your pet metric, it’s important not to neglect RPE. This is especially true if you’re using a smart trainer in ERG mode, where the app automatically adjusts the resistance of the trainer to match a given power target. Why?

Know Thyself: Why RPE Improves Your Training

The best athletes in the world aren’t the ones with the most accurate power meters, they’re the ones that are most in tune with their bodies. They’re able to assess how they are feeling for a given power output, compare that to how they know they usually feel for that output, and then adjust their effort accordingly to get the most out of the training session. If they’re feeling great, they can dial up the intensity and squeeze every last bit of benefit out of the interval instead of letting a number on a screen limit them. More importantly, they know when to dial things back if they’re having an off day, allowing them to recover more effectively so they can smash the next workout.

Mind over matter

The key to successfully using RPE is to be completely honest with yourself. That means allowing yourself to ignore your power output and heart rate. Everyone has good days and bad days. There are days when a given power target or heart rate feels like a walk in the park and other days where that same power (or heart rate) requires you to dig deep into the Courage Mines just to come close. 250W can be an RPE of 5 for one athlete and a 9 for another, but an RPE of 10 feels the same for everyone (horrible). That’s why being honest with yourself is key to RPE. While an RPE 7.5 is the same for everyone, only you can tell if you're actually riding at 7.5, and not a 5 or an 8.

Factors affecting your RPE

As a subjective measure, RPE can be influenced by several external factors. Say you didn’t get enough sleep last night, or you're dehydrated, or you didn’t eat enough before heading out to ride—all these factors can make a given effort feel harder. That effort feels harder because you're not functioning at your best. That means on a bad day an effort that is normally 95% of your FTP is 102% of your FTP today. Do not waste energy beating yourself up about not hitting a given number on a given day. If you focus on the feedback from your body (and mind) and hit the RPE that is intended, you’ll get the most out of your training.

Calibrating your internal RPE-ometer

We’ve established that to get the most out of your training, you need to use RPE. To get the most out of RPE, you need to understand how best to apply it.

In The Sufferfest app, RPE is intended to help you gauge how “hard” an interval, or set of intervals, should be in order to help you pace them effectively. Your internal sense of how hard you're going can—and should—change from the start of an interval to the end of an interval, and from the start of an interval set to the end of an interval set. RPE and power don’t need to have an exact 1:1 correlation, and often they won’t.

To give you a better picture of what you “should” be feeling relative to power and RPE targets displayed in the app, here are a few examples to think about:


Example 1: The 20 minute effort in Full Frontal

This is the effort used to set your FTP in the app. Unlike the traditional, stand alone 20-minute FTP test, this effort comes only a few minutes after a maximal 5-minute effort. This means that you're limited to riding right at FTP for this effort (assuming you truly emptied the tank during the 5-minute effort). While FTP correlates to 7.5 on the Sufferscale, that’s definitely not what the effort will feel like in this context. Since you start this effort pre-fatigued, it will feel harder than normal. By the time you’re 19 minutes in, you’ll be feeling more like a 9 than 7.5. HTFU, it will be over soon.

Example 2: The first and last 1-minute intervals in Revolver.


Revolver is a classic 1-minute-on / 1-minute-off, VO2-style workout. Done correctly, your average power of the first interval and the last interval should be the same. However, on an RPE scale they should feel very different. After 14 (15?) 1-minute intervals, that last one is going to sting quite a bit more than the first. Same power target, different RPE entirely.

Example 3: The one-minute interval in Full Frontal.

Crouched menacingly at the end of the Full Frontal fitness test, this is an all-out, maximal 1-minute effort. The ideal pacing strategy is to start at a near sprint and simply hold on for dear life. The first 10 seconds of that minute “feel easier” compared to the last 10 seconds, despite the entire effort technically being a “maximal” effort. Furthermore, your average power for those first 10 seconds will be higher than your average power for the last 10 seconds. Same RPE, different power output.


The Takeaways

Power meters have improved the accountability and quantifiability of training sessions, but a power meter can only tell you how many watts you’re pushing out. It can’t tell you how you’re feeling. The athletes who get the most out of their training are the ones that know a power meter and heart rate monitor don’t paint the full picture of how hard an interval is. The next time you’re doing an effort, remind yourself to focus on your body and how that effort feels. Is the power target easier than the last time you did the workout? Harder? Learn to balance the watts with the hows and you’ll be better able to maximize your Return on Suffering.

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