Demystifying RPE, the Borg Scale, and color coded effort levels

RPE is the gold standard in pregnancy and early into postpartum, and honestly it should be your main benchmark in your training day to day. Numbers only tell half the story. You can be getting through a zone 2 interval but feeling absolutely spent - yeah, you can hit the numbers but you feel like a 7 when you're working at a 4 - something's off.

This is why often a combo of HR and power can tell us a full story, but ultimately, asking yourself what each RPE feels like is going to take you the farthest even as your numbers shift over time. Your 5/10 should always feel like a 5/10 - in the same conditions. As you get fitter, that 5/10 should bring you a lower HR, coupled with faster paces and higher power output. It's a puzzle we never stop playing in fitness, and we're always solving and re-solving this puzzle.

Now - why does this matter in pregnancy, and what do all the numbers mean? Well, I'm going to overcomplicate this by layering in the Borg Scale, which you’ve no doubt heard of if you’ve googled pregnancy and effort levels, asked your doctor about these things, or have had a medical condition which suggests its use. There are a lot of practitioners and coaches out there who use this method, often because it's rooted in medicine and has some tie back to estimated heart rate. (But, I thought we don't care about HR in pregnancy?) Well, we don't. But the Borg scale HAS been widely adopted over time as the standard in pregnancy and therefore it deserves the explanation. This said, I *always* maintain a 1-10 RPE scale for my clients and for those of us used to using this as a benchmark, it's still the most foolproof measure.

Below, I'm breaking down what all of this means, and what it should feel like, and even a bit of what "color" it is on most popular color based zone programs that are widely used in apps and gyms. I love that the colors have become a more prominent part of training for athletes of all levels, because they put these terms in a visual place we can all understand.

When you start to work with HR, power, and pace, you can start to layer in more columns here where numbers match zones. And again, that’s continually shifting over time. But above all the numbers, it's most important to understand the FEEL of each one of those numbers, which is why I still default to RPE first over all other measures.

Working with heart rate (outside of pregnancy) power (we can still use power in pregnancy, and I recommend it!) and pace can help us really dial in fitness for specific races and fitness goals (increasing your FTP, for example), so as training cycles ebb and flow, those get incorporated with increasing importance.

But above all, in training the pregnant and postpartum athlete specifically, RPE remains the Queen of metrics!