Stress is Strain: Pt. 3 - Mental Strain (RPE, how does it feel?)

This article is Part 3 of a series on stress, strain, and load.

In this Stress is Strain series, I'm talking about the different ways we can measure and look at TRAINING stress. Keep in mind, stress and strain from daily life will have a direct impact on some of these metrics. Never discount what is going on in the "real world" and how it affects your training. That's where using the TrainingPeaks comments is super beneficial for your Paragon Training coaches. Reading those comments, we can better understand what you are dealing with on a daily basis (remember the article, "How to Have the Best Relationship with Your Coach"?)

It's time to wrap up our talk on training metrics. The final metric we'll talk about is our own internal pacing and "feel" mechanism.

Up this week: Mental Strain.

1. External load (Pace / Power)

2. Physiological Strain (Heart Rate / Lactate)

3. Mental Strain (RPE / How does it feel?)

Rate of Perceived Exertion (RPE)

Your Rate of Perceived Exertion (RPE) is the most subjective training metric you use. It's also the most beneficial if you have a well-tuned RPE sensor. It is extremely useful when technology doesn't work! (Gasp, I know.) I can promise you that, at some point, your HR monitor is going to be off, your gps will be inaccurate, and your power meter battery will die. It happens to all of us. The nice thing about RPE is that it's always with you. 

Learn more about RPE.

So let me break down the usefulness of RPE by showcasing two extremes:

Example 1: Mr. "It feels easy."

I hear this a lot. An athlete says that the pace or power "felt" slow, but when I look at the numbers, I can see that their HR or lactate numbers were actually pretty high, or higher than we wanted.

This is usually because the athlete is still building fitness and hasn't calibrated well enough to a wide range of intensities. Often, an athlete like this will say they have an RPE of only 3 or 4, but 20 minutes later they're HR is through the roof and they have to slow down. For this person, they may have realized how easy most training can and should be. It's also a function of fitness, because the fitter you are, the wider range of intensities we have available to us.

When Walk/Run Training Is Necessary

Somewhere between a 12:00-14:00 minute mile is where we transition from walking to running. For someone with a threshold at 8:00 mile pace, they can do an easy run at 11:00 mile pace and they are running 3:00 minutes per mile below threshold pace. For someone whose threshold pace is 10:00 per mile, 11:00 minute miles is only 1:00 minute slower than threshold pace and they are going to feel it! It's one reason a lot of you have walk/run combos in your long runs. We want to make sure that we are training at an aerobic intensity that is appropriate for each individual and not just turn every run into a threshold run

More Training Means Lower RPE

Another thing I've often found is that the MORE you train, the more you train at lower RPE levels. If you are only working out 3 days a week, you can afford for each day to be pretty hard and the mental toll of that isn't much. I don't think that going hard on all 3 of your training sessions in a week is the best approach for health, but I understand that desire to feel like something was accomplished. If you're training a high enough volume—say 40 miles of running a week—chances are that you'll be much more "okay" with chilling out at a VERY low RPE on the days you're supposed to. The mental toll (and also the benefit) comes from training consistently day after day, so we lower the RPE on the majority of sessions so that we can train MORE.

Example 2: Mrs. "It feels hard."

This scenario usually occurs when an athlete isn't used to following a very polarized training approach. It can sometimes be a fairly fit or advanced athlete, just one who hasn't truly gone hard in a while. Don't get me wrong, most training should be pretty easy at an RPE of 2-4. But sometimes you DO need to go super hard, and if you aren't used to going hard, the pain might surprise you!

It can vary among sports as well. This happens a lot on the bike. A lot of us get good at riding a reasonably steady tempo, but it's really more of a Z2/lower Z3 pace. When we try to do Z4 and even Z5 intervals, they sting! For this person, the RPE is probably calibrated correctly, but they aren't used to dealing with that RPE level in that modality yet. It has taken me YEARS to get good at suffering when swimming though, especially in a race, and I'm still learning. I find that most of us are pretty good at dealing with discomfort when running.

RPE Will Rise with Duration

Another interesting point is that for any given intensity level, RPE will rise to maintain that intensity as duration increases. Running at marathon pace might be an RPE of only 3 if you are doing 400 repeats at marathon pace. If you are running a marathon at marathon pace though, that RPE better be 10 by the end! It's why learning to scale the RPE as you go through a workout is also extremely important.

My final thought on RPE is that the fitter you are, the higher RPE you can maintain for longer. Elite athletes become VERY comfortable at high output levels. Their capacity to push hard for long periods of time is largely due to a massive aerobic base coupled with a high LT1 and LT2.

Depending on where you are at in your training progression as an athlete, your coach may be working with you to hold back, go slower, and control your pacing. But there will probably come a time when we as coaches specifically try to challenge you and push you out of your comfort zone. That's where individualization and specificity come in. 

Just remember this: Most training should be easy. Some training should be very hard!

Keep up the good work and remember to put your session RPE in TrainingPeaks!