Heart Rate Is a Gauge, Not a Governor: The Truth About Training Intensity
HowHow chasing exact numbers can sabotage your progress—and what to do instead
I recently received a message that perfectly illustrates informed heart rate monitoring. An athlete had just completed a prescribed 5K time trial—nailed the intensity exactly as planned. Her cooldown was supposed to be an easy jog back, but her heart rate was stuck in zone 3.
“I was jogging, but even at a snail’s pace, I was up into zone 3, so I figured to just walk,” she explained.
This was brilliant training intuition. She recognized the dissociation between her easy pace and elevated heart rate—a clear signal that her body was still processing the hard effort and needed true recovery, not continued training stimulus. Walking allowed her cardiovascular system to cool down rather than forcing another training effect.
This use of heart rate as feedback highlights a critical distinction: when pace and heart rate become dissociated, your monitor becomes invaluable information—but only when you understand what it’s telling you.
Here’s the fundamental principle: heart rate is a gauge, not a governor.
The Problem: When Numbers Rule Your Training
Most athletes fall into two destructive patterns with heart rate monitors.
Pattern 1: Complete Abandonment
You become frustrated when your pace feels “too slow” within prescribed zones. You abandon the monitor entirely and train purely by feel, which typically leads to chronic overreaching.
Pattern 2: Number Tyranny (More insidious)
You become trapped by the numbers, systematically training yourself slower by constantly adjusting effort to chase lagging physiological data.
Here’s the mechanism: when you see 151 bpm and your “target heart rate” is 150, you back off. When you see 149, you settle in. This settling effect creates a systematic drift toward the bottom of your intended stimulus range, progressively undermining training adaptation over time.
The root issue? Heart rate is inherently imprecise—it’s a lagging indicator that reflects what happened 10-30 seconds ago, not what’s happening now. Yet you treat your watch like a car speedometer, making micro-adjustments to numbers that are always behind the actual physiological reality.
What the Science Shows
Recent research on young cross-country skiers found that identical external training loads—same relative intensity and duration—produced significantly different internal loads based on individual perception and physiological capacity. Athletes who rated their low-intensity sessions higher on the RPE scale accumulated 60% more training load despite identical heart rate zone prescriptions.
More significantly, the athletes with higher internal loads during low-intensity training showed larger performance improvements (12.5% vs 10.7%), suggesting that your body’s effort perception often provides more accurate training guidance than heart rate zones alone.
Norwegian coach Olav Aleksander Bu, who guides Olympic champion Kristian Blummenfelt and Ironman World Champion Gustav Iden, emphasizes this precision problem: “How tired you feel isn’t necessarily an accurate measure of how hard you’re working. Pace may not be a good measure of intensity either because it varies so much between athletes and can vary even for the same athlete under different conditions.” His solution? Using multiple metrics—including lactate, heart rate, and even core body temperature—to triangulate true training intensity.
The %VO2max Advantage
Here’s why this matters: %VO2max outperforms %HRmax for gauging exercise intensity. While %HRmax relies on theoretical estimates (like 220 minus age) that vary widely by individual, %VO2max directly measures oxygen uptake, capturing aerobic effort through actual physiological data.
The good news? Your GPS smartwatch likely estimates %VO2max from %HRmax, providing a practical tool for real-time intensity monitoring. Check your device settings or companion app—most Garmin, Polar, Coros, and Apple Watches now include this feature. While not lab-accurate, these approximations offer valuable training guidance beyond simple heart rate numbers.
How to Train Smarter: Systematic Intensity Distribution
Research on training intensity distribution consistently shows that polarized and pyramidal models produce superior adaptations compared to threshold-heavy approaches. The key insight from 5-zone training models: specific intensity ranges have distinct relationships with performance gains.
High-quality aerobic training (approximately 62-73% of VO2max, roughly zones 1-2) correlates significantly with VO2max improvements, while threshold training (approximately 83-88% of VO2max, roughly zone 4) specifically enhances lactate threshold power.
This precision matters because, as Bu explains, “small changes have a huge consequence on the duration that you’re capable of holding” certain intensities. A 10% increase above your first lactate threshold can reduce sustainable duration by approximately 40%.
The systematic approach: When training architecture properly balances intensity distribution and recovery, heart rate naturally aligns with effort. Your body develops consistent physiological responses to training stimuli, making heart rate a reliable gauge—not a rigid rule.
Your Action Plan: Five Practical Applications
1. Use Heart Rate as Feedback, Not a Fixed Target
What to do: Treat heart rate data as a guide rather than a strict rule. When your heart rate doesn’t align with your perceived effort, adjust your effort to match your training goal.
Example: During easy recovery runs, if your heart rate remains elevated despite backing off to a shuffle, walk instead. Your body is telling you it needs true recovery, not continued training stimulus.
2. Determine Your Lactate Threshold and Maximum Heart Rate
If you have a Garmin or Coros GPS watch: Use the built-in lactate threshold test feature. This guided test provides two critical numbers:
Maximum Heart Rate: Your actual max HR (not an age-based estimate)
Lactate Threshold Heart Rate: Your threshold anchor for interval training
The watch will guide you through a progressive effort protocol, typically 10-15 minutes, analyzing your heart rate response to determine these values with reasonable accuracy.
If you don’t have a compatible watch: Perform a 30-minute hard run or cycle at maximum sustainable effort. Record the average heart rate for the last 20 minutes. This becomes your lactate threshold heart rate estimate.
How to use these numbers: Your lactate threshold heart rate becomes the foundation for setting interval training zones—specifically for the high-intensity work (zones 4-5). Your maximum heart rate helps establish the upper boundaries of your training zones. Both provide more accurate reference points than generic age-based formulas (220 minus age), which can be off by 10-20 beats per minute.
3. Implement Practical Threshold Protocols
What to do: Structure your high-intensity sessions using these distance-based threshold efforts. Run at a pace you could hold for roughly an hour—hard but sustainable—while letting your heart rate settle into the threshold range naturally.
For runners:
10 × 1K repeats: 1,000-meter efforts with 60-90 seconds recovery between efforts
5 × 2K repeats: 2,000-meter efforts with 2-minute recoveries
3-4 × 5K efforts: Continuous 5K at threshold pace with 3-4 minutes recovery (for more experienced athletes building longer threshold capacity)
6 × Mile repeats: Mile efforts with 90-second to 2-minute recoveries
For cyclists:
5 × 5K repeats: 5-kilometer efforts with 2-3 minute recoveries
3-4 × 10K repeats: 10-kilometer sustained efforts with 3-4 minute recoveries
Hill repeats: 3-5 minute climbs at threshold effort, easy spin-down recovery
Key insight: Focus on maintaining the prescribed effort and pace during work intervals. Your heart rate will naturally rise to threshold levels—you’re not chasing the number, you’re sustaining the effort that produces it. If your heart rate stays below threshold despite hard effort, that’s valuable feedback that you’re either not recovered or your threshold estimate needs adjustment.
4. Build a Polarized Training Week
What to do: Structure your training to include high volume of low-intensity work (62-73% VO2max, roughly zones 1-2) combined with strategic high-intensity sessions (83-88% VO2max, roughly zone 4).
Practical split for time-crunched athletes:
70-80% of weekly training time: Low-intensity aerobic work where you can maintain conversation
20-30% of weekly training time: Threshold and high-intensity intervals where talking becomes difficult
5. Combine Multiple Intensity Metrics
What to do: Use heart rate alongside perceived effort (RPE) and, when available, pace or power data. Cross-reference these metrics to get an accurate intensity assessment.
Why this matters: Heart rate lags by 10-30 seconds. Perceived effort often provides more immediate feedback about your actual training intensity, especially since research shows that higher perceived effort at the same heart rate correlates with better performance gains.
Device tip: Enable %VO2max display on your GPS watch for a more accurate real-time intensity gauge than %HRmax alone.
The Systematic Advantage
When you properly balance intensity distribution and recovery, heart rate naturally aligns with effort. This systematic precision explains why elite Norwegian athletes can train up to 10 hours daily while recreational athletes often struggle with much lower volumes.
The difference isn’t genetic superiority—it’s systematic precision in matching training stimulus to adaptive capacity.
The evidence is clear: polarized training models produce greater long-term adaptations than other approaches, particularly in highly trained athletes. But this effectiveness depends on treating heart rate as feedback, not a commandment.
Beyond the Watch
Until we have real-time lactate monitoring on our wrists, heart rate remains your best gauge—but only when you respect its limitations rather than worship its precision. The goal isn’t perfect numbers; it’s consistent progress through systematic application of training principles.
Your watch should inform training decisions, not make them.
When systematic training maintains the proper relationship between effort and response, heart rate becomes what it should be: a reliable gauge providing real-time feedback about your body’s adaptation to the training stimulus.
The athlete who chose to walk during her cooldown understood this intuitively. Now you have the systematic framework to apply this thinking to every training session.
Going Deeper: The Individual Application Challenge
The protocols and principles outlined here provide the systematic foundation for intelligent heart rate monitoring. But here’s what this article can’t address: your specific adaptation timeline, your individual recovery patterns, your unique constraints around work schedules and life responsibilities, and how to integrate these principles into a coherent training plan that matches your particular adventure goals.
This is where systematic assessment and individualized programming separate casual preparation from deliberate development. Understanding the principles is the first step. Applying them optimally to your situation—that’s where personalized coaching guidance makes the difference between following along and truly maximizing your limited training time.
Dive into the Research
Pind et al. (2023) found that identical external training loads produced 60% differences in internal load based on individual RPE ratings, with higher RPE athletes showing greater performance improvements (12.5% vs 10.7%). Pind, R., Purge, P., Mäestu, E., Vahtra, E., Hofmann, P., & Mäestu, J. (2023). Session rating of perceived exertion is different for similar intensity and duration prescribed low-intensity sessions and has a different effect on performance in young cross-country skiers. Journal of Strength and Conditioning Research, 37(1), 187–193.
Rivera-Köfler et al. (2025) demonstrated through systematic review that polarized and pyramidal training models produce greater VO2max enhancements and are more effective in elite athletes compared to threshold-based approaches. Rivera-Köfler, T., Varela-Sanz, A., Padrón-Cabo, A., Giráldez-García, M. A., & Munoz-Pérez, I. (2025). Effects of polarized training vs. other training intensity distribution models on physiological variables and endurance performance in different-level endurance athletes: A scoping review. Journal of Strength and Conditioning Research, 39(3), 373–385.
Watts et al. (2023) found that 5-zone training models better correlate with performance adaptations than 3-zone models, with high-quality aerobic training (T2 zone) correlating significantly with VO2max improvements. Watts, S. P., Binnie, M. J., Goods, P. S. R., Hewlett, J., Fahey-Gilmour, J., & Peeling, P. (2023). Demarcation of intensity from 3 to 5 zones aids in understanding physiological performance progression in highly trained under-23 rowing athletes. Journal of Strength and Conditioning Research, 37(11), e593–e600.
Docherty & Sporer (2000) highlighted that neuromuscular fatigue from endurance exercise significantly decreases strength training performance, establishing the foundation for understanding concurrent training interference. Docherty, D., & Sporer, B. (2000). A proposed model for examining the interference phenomenon between concurrent aerobic and strength training. Sports Medicine, 30(6), 385–394. DOI: 10.2165/00007256-200030060-00001
Wilson et al. (2012) demonstrated through meta-analysis that concurrent training results in compromised adaptations when endurance and strength training are performed with inadequate recovery between sessions. Wilson, J. M., Marin, P. J., Rhea, M. R., Wilson, S. M., Loenneke, J. P., & Anderson, J. C. (2012). Concurrent training: A meta-analysis examining interference of aerobic and resistance exercises. Journal of Strength and Conditioning Research, 26(8), 2293–2307. DOI: 10.1519/JSC.0b013e31823a3e2d
Bu (2024) explains the Norwegian method's systematic approach to training Olympic champions, emphasizing precision in intensity measurement using multiple physiological markers beyond heart rate alone. "How the Norwegian Training Method Powers World Champion Triathletes." TrainingPeaks Coach Blog, July 3, 2024. URL: https://www.trainingpeaks.com/coach-blog/norwegian-training-method-world-champion-triathletes/
Bu (2025) demonstrates how threshold heart rate training and heat adaptation protocols can improve VO2max and performance without adding joint stress, making training more accessible for recreational athletes. "An elite endurance coach explains how to boost a key metric for longevity with the 'Norwegian method'." AOL, May 8, 2025. URL: https://www.aol.com/elite-endurance-coach-explains-boost-102501641.html
