Running is a sport that requires you to find the fine line between pushing yourself and not overdoing it. One of the ways we do this is by avoiding the grey zone in training through using RPE or Rate of Perceived Exertion.
Distance running is different than other sports where there are often quick bouts of sprints followed by slower moments or a more relaxed pace.
Instead, we’re often on the road or trails many days a week and can find ourselves too easily doing every run at the same pace.
Learning how to run by effort is a game changer to prevent injury, increase enjoyment and most importantly to many runners improve their race day PR’s.
Regardless of how good your GPS running watch is, it can’t take into account how you’re truly feeling on any given day – including how fatigued your muscles feel, your level of motivation, life stress, or how well you’ve slept.
All of this affects the level of exertion you have to put forward, and this is where RPE is comes in.
In this article, everything you need to know about what RPE means, how to calculate your personal RPE, and why it’s important for you to understand it as a runner.
What is RPE in Running?
The Rate of Perceived Exertion is a way to measure the level of intensity of any physical activity we’re doing. Since it corresponds to perceived exertion, it relies upon how hard you feel your body is working at any given time.
It is primarily based on the physical sensations an individual experiences during physical activity. This includes:
- Increased heart rate
- Increased sweating
- Increased breathing rate
- Increased muscle fatigue
Since it’s based on perceived exertion, you might feel it’s subjective – but that’s a good thing, it’s the whole point really!
It helps you become more in tune with your body and know when it’s time to push harder and when it’s time to take it back a notch.
It was first developed in 1982 by the Swedish scientist Gunnar Borg. Hence, why it’s sometimes also referred to as the Borg Rating of Perceived Exertion (RPE).
Borg explains the idea of perceived exertion very well:
“Try to appraise your feeling of exertion as honestly as possible, without thinking about what the actual load is. Don’t underestimate it, but don’t over estimate it either.
It’s your own feeling of effort and exertion that’s important, not how it compares to other people’s.
What other people think is not important either. Look at the scale and the expressions and then give a number.”
RPE in Terms of Running
RPE is an excellent tool to use when it comes to running.
For runners, it means understanding that your body might be a better guide to a good workout than your watch.
- It’s not a specific pace
- It’s going to change daily based on sleep, stress, previous workouts, nutrition
- It takes into account changes in your physical environment, such as weather and terrain, and their effect on your body
- It’s a tool to help you train better (more on this below)
Hot and humid running is going to immediately increase your HR, which is going to increase the workload. Meanwhile getting super dehydrated is also going to increase HR and workload….not having slept is going to increase HR.
I think you get the idea. But learning to use effort means you can still get a good workout, without over taxing your body and setting back progress.
Borg RPE Scale vs Modified RPE Scale
The original Borg scale began at 6 and went all the way to 20. This scale corresponded with a person’s heart rate, that is it was designed to give you a fairly good estimate of your heart rate during activity.
To get your approximate heart rate using the original Borg RPE scale, you’d have to multiply your RPE by 10. For example, if your RPE is 14 then your heart rate would approximately be 140 (14 x 10).
This scale was made with an average healthy adult in mind. A person’s age and physical condition can affect their maximum heart rate and, for this reason, this scale might not match you entirely.
The modified RPE Scale, also known as the Borg Category-Ratio (CR), uses simple numbering ranging from 0-10 to help determine your level of exertion.
While both scales use a simple numerical list, there is a difference in the way they both measure perceived exertion.
The main difference between the two scales is that the original Borg scale is primarily a measure of exertion to determine heart rate, while the modified RPE scale is measured by a person’s breath – from deep breathing to shortened breaths or breathlessness.
Therefore, the original scale correlates with a person’s heart rate, while the modified RPE scale (Borg CR10 Scale) corresponds more with a feeling of breathlessness.
Here is a visual of a 1-10 RPE in running scale that you can start using to evaluate your runs.
I’ve tried to provide examples to help you better assess the way your effort level feels during a given workout. You will see slight variations on this chart and the numbers.
These are the numbers I use because it seems to help runners fully embrace easy running to get the maximum aerobic base building. But what matters most is you correctly listen to your body and then stick to whatever you use.
How Do I Calculate My RPE?
As you can see from the chart above this is less about a calculation and more about an honest assessment of how hard you are working during a given session.
The other thing you can calculate using your RPE is training load. This is one of the metrics you often see GPS watches attempting to figure out when showing you things like Unproductive or Peaking.
Defining a Hard RPE for Running
One of the ways that you can start to learn how easy should feel is by going out for a truly hard effort.
- Complete a good warm up with a little easy running
- Find a steep incline, run 4 x 30 seconds hard uphill
- Recover as much as needed between reps
More than likely, you will hit your max HR by the 3rd or 4th and should be nearly gasping for air if you are truly pushing hard. That is what a 10 feels like.
You should not be able to keep going at that pace for longer than 30 seconds.
Defining an Easy RPE
Now you’ve got hard and you want your easy runs to feel like the opposite.
- Can you sing a song without gasping?
- If you were running with a friend could you hold up your end of the conversation?
Remember this is not a specific pace as it can and will change due to a lot of factors. You should generally assume your easy pace is 60 seconds to 2 minutes slower than your marathon pace.
Recording Data Points
Just as you record pace and distance with each run, it’s time to start recording your RPE.
This is something we require of all the athletes that we coach.
- After finishing a workout take a moment to truly assess how it went
- Write down on a scale of 1-10 how hard it felt
- Review honestly with yourself if you pushed harder than you should have on a easy day
- Watch over time as you are able to either run faster or farther at the lower effort
Importance of RPE In Running
Why is this scale so useful and how can you put it in to practice?
For distance runners there is an excellent formula honed by Matt Fitzgerald and used by coaches around the world for decades that states we want to spend 80% of our running going easy and 20% going hard.
Unfortunately, many runners spend about 70% of their time in the grey zone. And 10% going truly hard and 20% therefore injured.
What is running in the grey zone?
Grey zone running is when you’re using pace as your guide, rather than effort. It usually means you are running slightly too hard on your easy days, a constant moderate intensity.
You aren’t going hard enough to get the training response of a speed workout and not easy enough to get the aerobic benefit of an easy run.
I often equate this to running around the 5-6 mark for most runners.
Benefits of Using RPE for Running
Now that we know what we want to avoid, here is how RPE can further improve our training and performance.
We know that doing all of our workouts at the same moderate intensity level leads to overtraining. The nervous system is constantly being taxed and not getting the recovery that comes from a true easy run.
This leads to feels of fatigue, burnout and usually injuries as form deteriorates.
Runners who find themselves hitting a plateau or noticing that every single run is the same pace are usually in the grey zone. Switching to a concerted effort to spend time going at a 4 most days and then 7-8 on hard workouts can pull them out of overtraining.
Learn more about the signs of overtraining >>
Learning to Listen To Your Body
Easy is not a pace.
But we seem to believe that it is which leads to a lot of problems.
After a night of poor sleep, your body is fatigued before you ever begin the run. If you force yourself to run what you think is easy based on a pace, the result is a higher heart rate, increased cortisol and very limited training benefits.
Easy runs build our aerobic capacity to run farther with less energy.
On the flipside, if you have a track workout on tap and it’s 85 degrees outside using this scale allows you to have a successful workout regardless of pace!
Because we MUST slow down in the heat due to the stress on the body, if we’re focused on an effort level we know that the work is paying off even if we didn’t hit an originally planned pace.
Increases Race Day Performance
After months of switching to a system where you are truly going easy and hard, you’ve allowed your body to build mileage consistently and not completely breakdown.
You arrive at the start line feeling fresher and now with a new found insight to how different levels of effort feel.
You’re better able to judge if you can start to pick up the pace at the halfway mark or if you’re in a good spot and simply need to keep holding on to where you are.
Hopefully this has helped you to better understand RPE in running and why it’s a tool that you need to start utilizing more often!
Looking for more running lingo broken down?
- Is a recovery run different than an easy run?
- What are fartleks?
- How to do a tempo run?
- When to use running strides?
- When to worry about running with a high heart rate?
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