By Coach Adolfo Salgueiro

As athletes, we have become so accustomed to technology that is has become an intrinsic part of our daily activity. Our GPS watches capture more data about more metrics than we even know what to do with. Even worse, we feel the need to share every single mile, every single plank and every single cross training session with the world, via our social media channels.

Your GPS Watch can measure many parameters, but only you can measure your effort.

As great as it is to have all our metrics a screen-tap away, the need to impress running friends and strangers with our daily achievements could be in detriment of your progress as runners. We know that slow runs are not sexy, they don’t get as many likes. We understand that running 11-minutes miles when you are a well-known Sub-4 marathoner is not what your brand is all about. But, when 80% of your training is supposed to be done at an easy pace, you either make peace with it or stop posting your easy runs. But I digress.

The time has come for us runners to understand that pace and effort are two different parameters. The primary measuring boundary is not how fast you are running, but how hard your body is working at any given time. The latter measurement is called the Perceived Rate of Exertion (PRE). It is also known as Rate of Perceived Effort (RPE).

According to the CDC, Perceived Exertion is how hard you feel like your body is working. It is based on the physical sensations a person experiences during physical activity, including increased heart rate, increased respiration or breathing rate, increased sweating, and muscle fatigue.

PRE can fluctuate dramatically depending on the athlete and the circumstances of any particular run. A 50% effort after a restful, full night of sleep, on a flat surface, at sea level during a cool, dry spring day, will have you running faster than if you ran a hilly course, at noon, in the middle of the summer, at 90% humidity, right after a big fight with your spouse.

There are a handful of scales to measure your PRE, and regardless of the one you prefer, they are all subjective and they end up evaluating the same thing, just using a different label. The most prominent are the Borg Rating of Perceived Exertion Scale and the RPE Scale.

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The Borg scale was developed by Swedish researcher Gunnar Borg, as a tool for measuring an individual\’s effort and exertion, breathlessness and fatigue during physical work. Its scale goes from 6 through 20 and it is set to roughly correlate heart rate. But, as revolutionary as it was when first proposed, that 6-20 range results very awkward to visualize. Plus, not everyone’s heart rate rests at 60 nor it maxes out at 200. Even experienced athletes have a challenging time figuring out where they are from 6-20 at any given moment when 6 is sitting/resting while 20 is maximal exertion. See the accompanying chart.

I personally prefer and recommend to my trained runners, an RPE Scale that goes from 1 to 10. This is nothing but a modification of Borg, but much easier to visualize both in theory and in practice. A Training at 5/10 RPE is at 50% of maximum effort instead of a 12/20 PRE. When you need to do a hill repeat at 7/10 RPE it is easy to figure out where 70% of maximum effort is, rather than a 16/20. See accompanying graphic.

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Because the cardinal sin of running is going too hard on easy days, the key to these scales is to figure out where your easy pace fits in. When your coach asks you to “run easy”, understand that you are asked to run at a 4-5/10 effort (40 to 50% of maximum effort), or whatever other parameter your coach has set up for that day. This is the sweet spot. It will feel like walking if you are not used to easy running but, with time, it will serve you well. Guaranteed.

As cliché as it sounds, always remember the GPS watch is an indicator of your performance, not the director of your training. It is the GPS watch that serves you, not the other way around. Stick to your plan and don’t get exerted more than prescribed. It is the key to maintaining yourself fresh, rested, injury-free and ready for hard workouts.

Have faith in the process. In a Runner’s World article from October 2021, Grete Waitz, former marathon world-record holder, Olympic medalist and nine-time winner of the New York City Marathon, was quoted stating: “Hurry slowly”. Believe me, she knew what she was talking about.