Easy, Steady, Hard: the RPE scale for runners, in plain words

What is RPE in running?

RPE is a number for effort as you feel it: breathing, legs, the whole sense of strain. It is not a guess at heart rate but a measurement in its own right, and in large lab studies it tracks heart rate and blood lactate closely across ages, sexes and fitness levels.

Heart rate lags, pace depends on ground and wind, and watches fail; effort is immediate. The skill is reading it honestly and checking it against something measurable.

What is the Borg RPE scale, and what is CR-10?

They are the two standard ways to put a number on effort, both from the Swedish psychologist Gunnar Borg. The original Borg scale runs from 6, no exertion, to 20, maximal. The later category-ratio scale, CR-10, runs from 0 to 10; it is what most coaches mean by “RPE 7.”

Borg’s 1982 paper set out both: a category scale with verbal anchors, and a newer ratio scale whose numbers behave more like proportions of effort. The ACSM position stand still classifies intensity with the 6 to 20 scale alongside heart rate.

The heart-rate columns are population averages: two runners at the same percentage of maximum can sit on opposite sides of a threshold. RPE, read honestly, tends to follow the threshold instead.

What RPE should an easy, steady or hard run be?

Easy is about 9 to 11 on the 6 to 20 scale: full sentences, holdable for an hour. Steady is about 12 to 14: short phrases. Hard is 15 and up, a few words at most. Easy sits below the first lactate threshold, Steady between the two, Hard at or above the second.

Those numbers come from Scherr and colleagues, who tested 2,560 people on treadmills and bikes. RPE correlated with heart rate at r = 0.74 and with blood lactate at r = 0.83, regardless of sex, age, heart disease, activity level or type of test.

Walk sits below them all. Individuals spread about 2 points either way, so the talk test is often more useful than the number.

Is the talk test accurate for running?

Surprisingly so, for the first boundary. In the lab, the point where speech stops being comfortable lines up closely with the ventilatory threshold, the breathing marker of the shift out of easy running. It is less useful for short hard intervals, and fools you if tested too soon after speeding up.

Persinger and colleagues found that where speech first became difficult, intensity was almost exactly at the ventilatory threshold; where speech was no longer comfortable, it was consistently above it. Foster and colleagues showed the talk test moved when the threshold moved, after blood donation and after training. A 2014 review called it valid, reliable and practical, though it may not suit high-intensity intervals.

• Test after settling. In Foster’s work the talk test took more than 2 minutes on average to turn negative after intensity rose. Speak a few minutes into a block.
• It errs toward passing. People often passed when they were in fact above the threshold. Unsure? You are probably not Easy.
• Say something real. A long sentence out loud, not a word in your head. Running alone, recite something you know. The neighbors will cope.

Is RPE better than heart rate for running?

Neither is better; they measure different things. RPE takes in the whole cost of a run: it reacts the moment you speed up, counts tired legs and heavy breathing, and works without a signal. Heart rate is slow at the start of an effort and moves with heat and fluid loss as well as work.

RPE also measures training load. Foster and colleagues showed that one rating for the whole session, given afterward, scored highly consistent with heart-rate methods across steady work, intervals and team sport. Multiplied by the session’s minutes, it is the load measure behind Foster’s earlier work on monotony and strain. More in training load for runners.

Why is my heart rate high when the run feels easy?

Usually because heart rate is reacting to something other than the work, most often heat or fluid loss. The reverse, a hard effort with a low heart rate, usually means the heart has not caught up yet. Neither is a diagnosis. Each is a reason to adjust today’s run.

• Heart rate climbing, effort unchanged, long run on a warm day. That is cardiac drift. In Montain and Coyle’s classic study of cyclists riding two hours in the heat, the heart-rate rise tracked dehydration almost exactly. Ease the pace to hold the effort.
• Effort high, heart rate still low, first minute of a rep. Heart rate takes time to rise, and wrist sensors lag further. Run the rep by feel and pace. See Apple Watch vs a chest strap.
• Both higher than usual at your normal easy pace. The day is harder than planned: heat, a short night, yesterday’s session. Slow down until the talk test passes.
• Effort low, heart rate low, pace quicker than usual. Often the best case: fitness. Enjoy it, and keep Easy easy.

This is training guidance, not medical advice. Chest pain, dizziness or breathlessness out of proportion to effort are reasons to stop and see a doctor, whatever your numbers say. See our health disclaimer.

How do you train by feel without running too hard?

Decide the effort before the run, check it with the talk test early, and keep most of your running Easy. Drift happens on easy days, when Easy becomes Steady because Steady feels productive. Seiler’s review of successful endurance athletes found about 80 percent of sessions at low intensity, about 20 percent dominated by high-intensity work.

Skip their volume; copy the proportion. Keep Easy easy so that Hard can be hard.

How does Gears use effort?

Gears names its efforts the way you feel them: Walk, Easy, Steady and Hard, each a colored pace range, placed from your own running and refined by every run with heart rate. Pace leads and heart rate guards: when your heart says an Easy or Steady pace is too much, the coach eases it.

Your feel goes back in, too: after a run, say how it felt (Easier, About right or Harder) and how each gear felt, and each answer tunes your personalized running zones.

What it doesn’t do: Gears doesn’t ask for an RPE number during the run, and it can’t feel your legs. The coach can tell you the pace is too quick for Easy; only you know whether you could say a full sentence.