What is RPE and How To Use It In Training for Beginners

In programming for weight training we have a few metrics that help us get the best and most reliable results. This of course are reps, sets, weight and something that some of you don’t know, which is relative intensity.

Relative intensity is measured either with RPE or RIR. We’ll now explain why this two scales are so important and how they affect our long term progress.

Relative intensity can be measured in few ways. What you really are measuring is how hard you trained. This is not the same as absolute intensity, which is literally the amount of weight on the bar.

In sprinting or cycling it’s a bit harder to judge how hard you really trained. It’s mostly based on the feeling of exertion. How hard you exerted yourself on a scale from 1 to 100 for example (1 being the lowest and 100 being the highest).

With weight training things are a bit more simple because we have repetitions and they do have a concrete ending.

There is a limit of how much reps you can do with a certain weight.

In weight training, we use two different scales to measure relative intensity. One is the “RPE scale” and the other is the “RIR scale”.

RPE stands for rate of perceived exertion while RIR means reps in reserve.

RPE – rate of perceived exertion

Let’s take 100lbs for example. Imagine you start doing reps with 100lbs and that this is a relatively heavy weight for you. At some point you won’t be able to do another rep. Let’s say that point is at 10 reps. If you tried to do the 11th rep you simply wouldn’t be able to do it.

This by definition means that your rep max with 100lbs is 10 reps.

We call this an RPE10 set, which is usually written down like this:

10×100@10RPE

So if our RM (rep max) with a certain weight is 10 reps, what is then RPE9? In this example, our RPE9 is 9reps.

Now this is where things can sometimes get confusing to people. RPE9 doesn’t mean 9 reps, RPE9 is a measurement of how hard we exerted ourselves. It simply means we had one rep left in the tank. If we can do 10 reps with 100lbs, one rep less is RPE9.

What would be our RPE9 if we could do 15 reps at RPE10 with 100lbs?

• Our RPE9 would be 14 reps.
• RPE8 would be 13reps.
• RPE7 would be 12reps.

This is why RPE is confusing to some people. People try to use it as a “feeling” measurement, they try to use it based on their subjective feelings. They measure how hard the set felt and not how far away from failure they really were.

This is how the RPE scale should be used in weight training:

RPE SCALE:

• <5 – (warmup weight)
• 6 – you for sure had 4 reps left in the tank
• 6.5 – you for sure had 3 reps in the tank but 4th is questionable
• 7 – you had 3 reps in the tank
• 7.5 – you definitively had 2 reps in the tank but 3rd is questionable
• 8 – you had 2 reps in the tank
• 8.5 – you could definitively do another rep but another one on top of that is questionable
• 9 – you had one more rep
• 9.5 – the next rep is highly questionable
• 10 – you definitively couldn’t do another rep

Because of somewhat confusing application of RPE, the RIR scale is born. RIR is a more accurate representation of what we’re trying to accomplish here.

What we’re really trying to measure is how far away from failure we are.

RIR – reps in reserve

In comparison to RPE scale, RIR scale is super straight forward:

RIR SCALE:

• 1RIR – 1 rep in the tank (meaning you could do another rep but no more)
• 2RIR- 2 reps in the tank (meaning you can definitively do 2 more reps)
• 3RIR – 3 reps in the tank (meaning you can definitively do 3 more reps)
• 4RIR – 4 reps in the tank (meaning you can definitively do 4 more reps)

RIR scale is more straight forward and it pretty much completely eliminates the false assumption that there is a subjective interpretation.

You simply answer to the question – how many more reps could I do if I hadn’t stop doing them?

When we’re trying to achieve results in weight training there are so much moving parts on which we need to keep an eye on.

This is why you want to keep things as simple as possible while still covering all the things that affects your training.

Hopefully this article helped you understand relative intensity more.