Rate of Perceived Exertion (RPE): Why "Feel" Is the Most Underrated Training Instrument

Opening: The Student Who Treated His Heart Rate Monitor Like Gospel

A few years ago, I coached a very dedicated office-worker cyclist—let’s call him A-Kai. He did his homework thoroughly, watched every training channel out there, and bought a power meter, heart rate strap, and a high-end cycling computer. He had enough data to run a small laboratory. But every time we rode together, I felt something was off.

One time, we planned a hill climb at the base of Yangmingshan. That day, Taipei’s humidity was so high it felt like a steam room, and he’d only slept about four and a half hours the night before. Midway up the climb, his heart rate just wouldn’t rise. Staring at his computer showing “only 150-something bpm,” he forced himself to speed up, saying, “My heart rate isn’t going up today—I must not be trying hard enough.” As a result, his legs were dead for the next three days after that ride, and his long-distance session the following week completely fell apart.

I later asked him one question: “At that moment, how did your body feel—did you still have something in reserve, or were you already hanging on by a thread?” He paused and said, “Actually, my legs were burning and I could barely breathe, but since the heart rate number wasn’t there, I didn’t trust how I felt.”

That’s why I wanted to write this article. Athletes of our generation are increasingly trusting the numbers on our devices while trusting the signals from our own bodies less and less. But here’s the truth—heart rate drifts due to sleep, caffeine, dehydration, and temperature; power meters need to be re-zeroed with temperature changes; GPS can wander. The one “sensor” that has been with you since birth, integrating information from your heart, lungs, muscles, metabolism, and even your psychological state, is your Rating of Perceived Exertion (RPE). Today, let’s properly understand, calibrate, and put to use this severely underrated instrument.

What Is RPE? First, Meet the Two Scales

The core concept of RPE is simple: use a number to quantify “how tired, how breathless, how hard you feel right now.” It was developed by Swedish physiologist Gunnar Borg decades ago, and the insight behind it is profound—the body’s overall perception of exercise load actually integrates a host of physiological signals like heart rate, breathing, sweating, and muscle soreness, making it an incredibly valuable composite metric.

In practice today, there are two scales you’ll encounter most often. You absolutely need to know the difference, because their number ranges are completely different, and mixing them up will cause major confusion.

The Borg 6–20 Scale (Original Version)

This is the classic version, ranging from 6 to 20. Many people ask when they first see it: “Why doesn’t it start at 0 or 1? Why this odd 6 to 20?”

The answer relates to heart rate. When Borg designed it, he deliberately made the scale numbers, when multiplied by 10, roughly correspond to the heart rate of an average adult at that intensity. So an RPE of 6 roughly corresponds to a resting heart rate of 60 bpm, and an RPE of 20 corresponds to a near-maximal heart rate of around 200 bpm. An RPE of 13 (“somewhat hard”) roughly lands around 130 bpm—of course, this is only a rough correspondence, not a precise measurement, and certainly not a substitute for actual heart rate monitoring.

Worth noting: a study on young Taiwanese men actually measured the relationship between the Borg 6–20 scale and heart rate, finding a regression relationship of approximately “heart rate = 8.88 × RPE + 38.2” (in bpm) during dynamic exercise. This relationship is strongest in whole-body dynamic exercise (like cycling or running); when exercise becomes static or partially static (like isometric contractions in weight training), the correlation between heart rate and RPE weakens noticeably. This also reminds us: the correspondence between RPE and heart rate is most applicable in aerobic, whole-body, dynamic contexts like cycling and running.

The Borg CR10 Scale (Category-Ratio Version)

Borg later developed a 0-to-10 (practically extending beyond 10) category-ratio scale (CR10). It’s more intuitive—0 is no effort at all (lying down resting), and 10 is the absolute limit you’ve ever pushed yourself to.

CR10 is particularly popular in clinical settings, commonly used to assess the severity of dyspnea (breathlessness), chest pain, and musculoskeletal pain. It’s also popular in the weight training community because it pairs well with the concept of “reps in reserve” (RIR).

My practical recommendation: For general cyclists and runners, I almost always use CR10 or an even more plain-spoken 0–10 version, because it’s easy to remember and communicate. I only pull out the 6–20 version for endurance training where heart rate correlation is needed. Unless otherwise noted, everything in this article refers to the 0–10 scale.

What Exactly Does RPE Measure? Breaking Down Its Physiological Basis

Many people assume RPE is just “shouting out a random number based on a feeling,” but that’s not the case. When your brain produces that number, it’s integrating a massive amount of physiological input in the background:

• Cardiopulmonary signals: Heart rate, breathing frequency, and the effort of ventilation. When you start “gasping so hard you can’t finish a full sentence,” it usually means you’ve crossed a metabolic threshold.
• Local muscle signals: Muscle soreness, burning, and weakness, related to lactate accumulation and changes in the muscle’s ionic environment.
• Body temperature and sweating: Riding in Taiwan’s summer, the same power feels significantly harder than in winter because your body has to expend extra energy to dissipate heat.
• Metabolic substrate status: When glycogen is nearly depleted (commonly known as “hitting the wall”), the same pace suddenly becomes unbearably painful.
• Psychological and central state: Sleep, stress, and motivation all play a role. This is why your training feels especially “heavy” during exam weeks or overtime periods.

So RPE is actually a centrally integrated output. Its beauty lies precisely in this—it doesn’t care why you’re tired today; it simply and faithfully reflects “how heavy your overall load is right now.” This is exactly what a single heart rate or power number cannot do. A power meter doesn’t know you didn’t sleep last night, doesn’t know you’re coming down with a cold, doesn’t know you’re severely dehydrated. But your RPE knows.

RPE, Heart Rate, Power: How Should the Three Divide the Work?

I often tell my athletes that these three tools don’t replace each other; each has its own role. The table below summarizes their characteristics:

Metric	What It Reflects	Strengths	Limitations
Power (watts)	The mechanical work you “actually output”	Objective, real-time, unaffected by environment, allows precise training plans	Expensive, only available on the bike, doesn’t reflect the body’s cost
Heart rate (bpm)	The body’s “internal response”	Reflects physiological load, affordable and accessible	Has lag, subject to drift from caffeine/sleep/temperature/dehydration
RPE (perceived exertion)	Centrally integrated “overall load sensation”	Free, always with you, integrates all signals, works for any exercise	Subjective, requires practice to calibrate, beginners often inaccurate

See the difference? Power is “how hard you’re pedaling,” heart rate is “how hard your body is working,” and RPE is “how tired you feel as a whole person.” The ideal state is to cross-reference all three. When you notice one day that “at the same power, heart rate is low, but RPE is high,” that’s usually your body sending you a warning—it could be accumulated fatigue, dehydration, or the onset of illness. This kind of divergence often predicts, earlier than any single number, that it’s time to hit the brakes.

Practical Method One: Turning RPE into Your Training Intensity Map

Knowing the concept alone isn’t enough; you need to be able to use it for planning. The table below is the 0–10 RPE intensity reference I actually use with my athletes. You can print it out and stick it in front of your trainer:

RPE	Subjective Feeling	Ability to Speak	Approximate Intensity Zone	Typical Use
1–2	Almost no effort	Can sing	Recovery zone	Warm-up, cool-down, recovery days
3–4	Easy, sustainable for a long time	Can chat comfortably	Aerobic endurance (Zone 2)	Base-building long rides, building the aerobic engine
5–6	Somewhat hard but manageable	Short sentences yes, long sentences get breathless	Tempo / Sweet spot	Tempo rides, steady long climbs
7–8	Clearly hard, starting to feel uncomfortable	Can only get out a few words	Lactate threshold ~ VO2max	Threshold intervals, race pace
9	Very painful, about to crack	Almost can’t speak	Above VO2max	Short sprint intervals
10	All-out, completely emptied	Cannot speak at all	Maximal	Sprint finishes, maximal testing

A Sample Cycling Plan Entirely Structured by RPE

Many people think you can’t train well without a power meter—that’s a huge misconception. Below is a weekly plan I designed for an athlete who had no power meter, only a basic cycling computer, entirely directed by RPE:

Training Day	Content	Target RPE	Key Reminders
Tuesday	60 min aerobic base	3–4 throughout	Better too easy than sneaking in extra speed
Wednesday	Rest or 20 min walk	1	Active recovery, don’t push it
Thursday	Threshold intervals 4×8 min	7–8 each, 3 min rest between dropping to 2	Last interval must be held without fading
Saturday	Long ride 90–150 min	3–4 throughout, occasional climbs to 5	Practice fueling and heat tolerance, don’t chase KOMs
Sunday	VO2max intervals 5×3 min	9 each, 3 min rest between	Deliberately hold back on the first two, don’t blow up early

The soul of this plan is: RPE automatically adapts to your circumstances. Take Thursday’s threshold intervals—on a cool winter day, you might ride faster to reach RPE 7; on a muggy summer day, you’ll reach RPE 7 at a slower pace. Either way, the “training stimulus” you give your heart, lungs, and muscles is the same. This is something a power meter actually can’t do—if you stubbornly stare at a fixed wattage and force that number in summer, you’re likely to overtrain and blow up at home afterward.

Practical Method Two: Individual Calibration—This Is the Soul of RPE

This is the section I most want to emphasize in this entire article. RPE is not a “one-size-fits-all standard ruler”; rather, everyone must calibrate their own personal scale. When two people both say “RPE 7,” your 7 and my 7 may correspond to very different physiological states. The most common problem for beginners is “RPE compression”—they call every slightly hard effort an 8, 9, or 10, because they haven’t yet experienced a true limit and don’t know what a 10 looks like.

Calibration Steps: How to Develop an Accurate RPE

1. Establish anchors: You must personally experience both ends of the scale. Do one true all-out test (e.g., a 3-minute or 5-minute maximal effort, riding until you genuinely feel like throwing up), and you’ll know what RPE 10 is. Also do a super-easy recovery ride to feel what RPE 2 is like. With the upper and lower anchors in place, the gradations in between will hold firm.

2. Cross-check afterward: This is the most effective practice. Call your RPE during the workout, then go home and compare it against your heart rate or power data. If you “felt like RPE 5” but the data shows you were actually above threshold, you underestimated; and vice versa. Do this for a few weeks, and your accuracy will improve dramatically.

3. Talk test: Taiwanese cyclists love to chat on group rides, which happens to be a natural calibration tool. Being able to speak in full, easy sentences = RPE 3–4; only short sentences = RPE 5–6; only single words = RPE 7 and above. This is a zero-cost, extremely practical rough calibration method.

4. Record and review: Spend 30 seconds after each workout writing down the “overall session RPE” in your notes. Over time, you’ll find your perception becoming increasingly reliable.

Quantifying Training Load with Session RPE

Here’s a very practical advanced application that many pro teams use: Session RPE × training duration in minutes = training load (arbitrary units, AU).

Example: a 90-minute long ride with an overall RPE of 4 gives a training load of 4 × 90 = 360 AU. A 60-minute interval session with an overall RPE of 7 gives a load of 7 × 60 = 420 AU.

Add up your daily AU, and you can track your weekly total load and avoid sudden spikes. A good rule of thumb: keep weekly load increases to roughly 10% or less to avoid big jumps. This method is completely free, yet it can effectively help you avoid the vicious cycle of “training hard one week, then paying for it with an injury the next.” Here’s an example of weekly load tracking:

Day	Duration (min)	Session RPE	Training Load (AU)
Tuesday	60	4	240
Thursday	60	7	420
Saturday	120	4	480
Sunday	75	8	600
Weekly Total	315	—	1740

If you want to add volume next week, keep the total AU to around 1900 (about +10%), rather than impulsively doubling it. This approach of “managing objective load with subjective perception” is exactly what makes RPE so compelling.

Advanced: Using the Acute-to-Chronic Workload Ratio to Catch Overtraining

If you want to go one level deeper, you can extend Session RPE into a comparison of “acute load vs. chronic load.” The method is simple: add up the AU from the last 7 days (acute, representing your fatigue “this week”), then divide by the average weekly AU over roughly the last 4 weeks (chronic, representing the “fitness base you’ve built long-term”). Most people are relatively safe maintaining this ratio between roughly 0.8 and 1.3; once it spikes above 1.5 in a given week, it means you’re “jumping too fast” relative to your long-term base, and the risk of injury and illness rises significantly.

I want to emphasize here: these numbers are empirical reference ranges, not ironclad rules. Everyone’s constitution, age, and recovery ability differ. Their value isn’t in precision, but in giving you an “objective brake signal” to prevent blindly adding volume while you’re on a high. When coaching athletes, I often see people who are pumped for two or three consecutive weeks, with AU climbing steadily, then suddenly get a cold or knee pain in the fourth week—looking back, the acute-to-chronic ratio had already blown past the limit. The body’s debts always come due.

Here’s how to quickly interpret your status with a simple table:

Acute-to-Chronic Ratio	Plain-Language Interpretation	Recommended Action
Below 0.8	Training less than usual, possibly deloading or slacking	Consider moderate increases, or this may be an intentional deload period
0.8 – 1.3	Sweet spot, training and recovery roughly balanced	Maintain the rhythm, steady progress
1.3 – 1.5	Starting to run high, pay attention to body signals	Monitor sleep, morning heart rate, and mood; don’t add more
Above 1.5	Jumping too fast relative to long-term base	Proactively schedule recovery days, pull intensity back

Again, this isn’t about becoming a slave to numbers; it’s about having an objective buffer zone to remind you to cool down when you “subjectively want to push.” RPE provides the raw feeling, and this ratio helps you turn that feeling into a manageable trend.

RPE in Taiwan’s Local Real-World Scenarios

With the theory covered, I want to spend a full section on why RPE is especially useful in Taiwan’s environment, because our riding conditions really are quite different from the assumptions in Western textbooks.

Scenario One: Summer Heat and the “Cooling Tax”

Taiwan’s summers routinely hit 32°C and above with humidity starting at 80%. This hot, humid environment is a massive challenge for endurance athletes. With high humidity, sweat doesn’t evaporate, cooling efficiency drops dramatically, and the body has to shunt more blood to the skin for heat dissipation, leaving less for the legs. The result is—at the same power and same pace, RPE in summer is noticeably higher than in winter.

If you stubbornly stare at the power or pace numbers you trained with in winter and force yourself to hit them, you’re not training—you’re gambling with heat exhaustion. My principle for athletes is straightforward: in summer, let RPE take the wheel. If the plan says “threshold intervals at RPE 7,” then ride at RPE 7 and stop there, even if your watts are 20 to 30 lower than in winter. That’s normal and correct. Training stimulus comes from “the level of effort your body perceives,” not the pretty number on your computer.

In practice, I also recommend scheduling high-intensity sessions in summer for early morning or evening, avoiding midday; hydrate proactively and in small, frequent amounts; and if your RPE inexplicably spikes mid-ride, accompanied by dizziness, goosebumps, or cessation of sweating, that’s not an RPE problem—it’s a precursor to heat illness. Stop immediately, get to shade, cool down, and seek medical attention if severe.

Scenario Two: The Art of Pacing on Classic Long Climbs

Taiwan’s climbing routes are world-class, from short suburban climbs like Yangmingshan and Fengguizui to ultra-long climbs like Wuling that take three or four hours. Climbing is where RPE delivers the most value, because climbs are where people are most prone to “starting too hot and blowing up at the end.”

I often tell athletes preparing to challenge Wuling: for the first third, keep your RPE at a level where “you feel like you might be riding too slowly” (around 4 to 5), saving your bullets for the steep sections after Cingjing. Too many people get swept up by the atmosphere and their riding buddies, starting at RPE 7 or 8, feeling awesome—only to cramp up or end up walking their bike on the hardest section at the end. There’s no luck on a climb; what you owe in the front, you pay back with interest in the back. RPE is the rein in your hands that says “don’t overdo it.”

Scenario Three: Eating Out, Fueling, and RPE Signals

Taiwan’s convenience of eating out is great, but it also makes many office-worker cyclists’ “pre-training fuel” quite unstable. Here’s a very practical observation: if you’re on a long ride and your RPE suddenly spikes for no apparent reason in the latter half, with legs feeling like lead, that’s often a signal of glycogen depletion (hitting the wall). This isn’t a cue to grit your teeth and push through; it’s a reminder that your fueling has fallen behind.

As a general rule, for moderate-to-high intensity rides lasting beyond roughly 60 to 90 minutes, you should start regularly consuming carbohydrates (roughly tens of grams per hour, with the exact amount varying by individual). If you head out having only had a sugary drink and a piece of bread, you’re very likely to hit the wall later. Learning to read “an abnormal RPE spike” as a “time to fuel” signal will make the second half of your long rides much more stable. As for precise carbohydrate amounts and personalized formulas, those depend on body weight, intensity, and gastrointestinal tolerance—I recommend consulting a sports nutritionist for individualized adjustments.

A Second Case Study: Using RPE for Weight Loss and Health in an Office Worker

The story of A-Kai earlier was about an advanced cyclist. Let me share a completely different type of athlete—let’s call her Pei-Chi. She was in her early forties, a sedentary office worker with a laundry list of red flags on her health check report. Her doctor recommended she start regular exercise and manage her weight. Her biggest initial frustration was: “Coach, I can’t understand all those heart rate zones, power, and all that—it’s too complicated. I just want to move a bit and be healthier.”

For someone like her, RPE is a godsend. I didn’t give her any expensive devices; I only taught her one sentence: “Ride at an intensity where you can talk easily but can’t sing.” That’s the aerobic zone of RPE 3 to 4. She rode along the riverside and took indoor cycling classes, self-monitoring the whole time with the talk test.

This approach had three benefits. First, the barrier to entry was extremely low—she wouldn’t quit because she “couldn’t understand the data.” Second, it was safe. She had mild hypertension, and I specifically advised her: keep exercise intensity at a “comfortable, sustainable” level; if any chest tightness, dizziness, or abnormal breathlessness occurs, stop immediately and seek medical attention; and be sure to take medication as prescribed and attend regular follow-ups—exercise is a supplement, not a replacement for medical care. Third, it was sustainable. She didn’t have to exhaust herself every time, which allowed her to keep moving consistently over the long term.

Three months later, not only had her weight and blood pressure numbers moved in the right direction (please defer to her doctor’s tracking for actual figures), but more importantly, she said: “I actually ‘enjoy’ exercise now, because it’s no longer an exam I can never pass.” That’s the greatest significance of RPE for the general healthy population—it shifts exercise from ‘chasing cold, hard numbers’ back to ‘listening to your own body.’

I also want to offer a serious reminder here: for friends with chronic conditions like Pei-Chi (hypertension, diabetes, heart disease, etc.), before starting any exercise program, you must first discuss it with your doctor and undergo an individualized assessment to confirm appropriate exercise types and intensity limits. RPE is an excellent self-monitoring tool, but it cannot replace professional medical judgment.

Common Mistakes and Corrections

In my years of coaching, I’ve found that the pitfalls people fall into with RPE are highly repetitive. Let’s address them all at once.

Mistake One: Treating RPE as a “Willpower Contest”

Many people think “if I didn’t hit RPE 9 today, I didn’t try hard enough.” Wrong. Recovery days at RPE 2 and long rides at RPE 3–4 are supposed to be easy—that’s by design. If every single workout is RPE 7 or above, you’re not diligent; you’re digging a chronic hole for yourself. Training progress happens during recovery, not in the moment you drain yourself dry.

Mistake Two: The Beginner’s “RPE Compression”

As mentioned earlier, beginners often call moderate efforts 9 or 10. The fix is the “establish anchors” method described earlier—do a true all-out test. Once you’ve experienced the real ceiling, your scale will stretch open and become accurate.

Mistake Three: Ignoring the Environment’s Effect on RPE

Taiwan’s summers are humid and hot. At the same power, perceived effort is significantly higher. This doesn’t mean you’ve gotten weaker; it means your body is diverting attention to cooling. The correct approach: on hot days, accept that pace/power will drop, and let RPE be the commander-in-chief. Forcing the numbers you could hit in cooler weather is a common prelude to heat exhaustion and heat stroke. Conversely, when you go from sea level to high altitude like Wuling, your actual output at the same RPE will drop—that’s also normal, so don’t beat yourself up.

Mistake Four: Completely Rejecting Objective Tools

I advocate for RPE, but that doesn’t mean you should throw away your heart rate monitor. The strongest approach is triangulation: cross-reference RPE, heart rate, and power. As mentioned earlier, when the three diverge (e.g., low heart rate but high RPE at the same power), that’s often the body’s most honest fatigue warning, more worthy of serious attention than any single number.

Mistake Five: Ignoring the Body’s “Danger Signals”

This point is especially important. RPE measures “level of exertion,” but some sensations aren’t just plain tiredness—they’re warnings: chest tightness or pressure during exercise, cold sweats, dizziness, palpitations, unusual breathlessness, or nausea. These are not a matter of “RPE is high, just push through.” The correct response is to stop immediately and seek medical attention if necessary. Taiwan’s National Health Insurance makes seeing a doctor convenient, so don’t dismiss these signals because you “don’t want to interrupt training.” RPE is a training tool, not an excuse to swallow your body’s alarm bells.

Actionable Advice for Readers at Different Levels

If You’re a Complete Beginner

Don’t rush to chase numbers. What you most need to do at this stage is learn to distinguish “easy” from “hard.” Use the simplest talk test: if you can chat while riding, that’s the aerobic zone where you should spend most of your time (RPE 3–4). Put 80% of your training time there, and only touch high intensity with the remaining 20%. Remember the old saying: most people don’t train too little—they train too hard and too chaotically.

If You’re an Intermediate Enthusiast

Start doing the “cross-check afterward” homework. Call your RPE during each session, then compare it against heart rate or power data when you get home. Do this for a few weeks to calibrate your scale properly. At the same time, start recording Session RPE and calculating weekly training load (AU), managing your progression with the ~10% rule. You’ll find that when you can accurately predict your data from feel, your training quality will jump to a new level.

If You’re Already Experienced / Preparing for a Race

RPE’s greatest value for you lies in pacing decisions on race day. On race day, adrenaline is through the roof, heart rate readings are unreliable, and the weather is different from training—what often saves you is RPE. For a long climb like Wuling, you absolutely must hold back in the early section at an RPE where you “know you still have something left,” saving your bullets for the end. Too many people get swept up by the atmosphere and start at RPE 8, only to completely blow up in the final 10 kilometers. Those who know how to hold their RPE back at the starting line are the ones who truly know how to race.

A FAQ Section

Q: I only have a basic cycling computer, no power meter. Can I train properly?
A: Absolutely. That’s what this entire article has been about. RPE combined with the talk test is enough to support a solid endurance training plan. A power meter is a bonus, not a necessity.

Q: RPE is so subjective—isn’t it inaccurate?
A: A single reading does have error, but through establishing anchors, cross-checking afterward, and consistent recording, your RPE can be calibrated to be quite reliable. Moreover, it integrates fatigue and environmental information that heart rate and power can’t see. This “imprecise comprehensiveness” often beats “precise one-sidedness.”

Q: Do cold medications or coffee affect RPE?
A: Caffeine may make you “feel less tired” at the same effort—that’s one of its effects. Illness or fever, on the other hand, will cause RPE to spike abnormally—which is actually a good thing, as it’s your body telling you to rest today. If you’re sick, especially with a fever, stop training and seek medical attention as appropriate. Don’t push through.

Q: Can RPE be used for weight training?
A: Yes, and it works very well. The lifting community often pairs RPE with “reps in reserve (RIR)”: RPE 10 means failure with zero reps left, RPE 8 means roughly 2 reps left. However, note that as mentioned earlier, the correspondence between heart rate and RPE weakens during static/isometric efforts, so don’t try to force weight training RPE onto heart rate.

Q: Is the “Zone 2” shown on my sports watch the same as RPE 3–4?
A: Roughly similar, but don’t treat them as identical. Your watch’s heart rate zones are calculated from the max heart rate you’ve set, and if that max heart rate is wrong (many people use crude formulas like “220 minus age”), the zones will be entirely off. RPE isn’t affected by this problem. My advice is to look at both together: if you “feel easy (RPE 3)” but your watch says you’re in Zone 4, your heart rate zone settings are probably inaccurate, and it’s worth doing a proper test to recalibrate.

Q: As I get older, will RPE become inaccurate?
A: RPE is a relatively robust tool that works across ages—that’s one of its advantages: it doesn’t rely on max heart rate, which declines with age. Older adults may actually be better suited to RPE, because certain medications (e.g., some blood pressure drugs) can blunt the heart rate response, rendering heart rate numbers meaningless. In that case, the body’s overall perceived effort is actually more reliable. Of course, for older adults with chronic conditions or on medication, exercise plans must first be discussed with a doctor.

Q: How do I know my RPE is calibrated well enough?
A: A simple test: do the same interval session several times, predict beforehand “this interval will probably be around X watts / Y pace,” then compare against actual data afterward. When your predictions get closer and closer to reality, your internal scale is well calibrated. This is a skill you can keep honing, not something you’re born with.

Conclusion: Train Your Feelings into an Instrument

Back to A-Kai at the beginning. It took me about a month to recalibrate his RPE. I had him do an all-out test to stretch open the upper end of his scale, and deliberately scheduled several “ridiculously easy” recovery rides so he could feel the lower end. He called his RPE before each session and compared it against heart rate afterward. Three or four weeks later, he said something that gave me a great sense of accomplishment: “Coach, now I can tell halfway through a ride how I’m doing today. The numbers have become just a confirmation tool.”

That’s exactly the state I want to bring you to. Instruments are great, but instruments are external; RPE is yours. When you can train your subjective perception into a reliable instrument, you’ll have a coach that never runs out of battery, never drifts, and is with you everywhere—your own body.

Heart rate monitors drift, power meters need zeroing, GPS wanders, but that sensor that has been with you since birth, integrating all the signals from your entire body, has always been there. Learn to trust it, calibrate it, and use it well, and your training will be transformed. Next time before you get on the bike, ask yourself: “Today, how do I feel?”—that’s the best starting point for training.

---

This article is educational content and cannot replace individual diagnosis and treatment advice from a physician, physical therapist, or nutritionist. If you have a history of cardiovascular disease, hypertension, diabetes, or other chronic conditions, or if you experience abnormal symptoms such as chest pain, palpitations, or dizziness during exercise, please consult a qualified medical professional and undergo an individualized assessment first.

References

• Relationships of Borg’s RPE 6-20 scale and heart rate in dynamic and static exercises among a sample of young Taiwanese men (PubMed): https://pubmed.ncbi.nlm.nih.gov/24665812/
• Rate of Perceived Exertion (RPE) Scale, Cleveland Clinic: https://my.clevelandclinic.org/health/articles/17450-rated-perceived-exertion-rpe-scale
• Borg Rating Of Perceived Exertion, Physiopedia: https://www.physio-pedia.com/Borg_Rating_Of_Perceived_Exertion
• Rating of perceived exertion, Wikipedia: https://en.wikipedia.org/wiki/Rating_of_perceived_exertion

Related Reading

• RPE and sRPE: The Cheapest and Most Underrated Training Load Monitor
• Subjective Fatigue Assessment After Running: Applications of the RPE Scale and POMS Questionnaire
• RPE Feel-Based Pacing: Research on the Accuracy of Subjective Fatigue Perception in Long-Distance Running
• RPE Perceived Effort in Running: How to Use Subjective Feel to Correct Your Pace