(The Science Behind Heart Rate–Driven Training, When It’s Appropriate to Use, and Why We Don’t Believe It’s Always Useful)
Heart rate training has increased in popularity—and now more than ever, we have easier access to wearable devices that help us monitor it. Our heart rate can help us determine which energy systems our runs are primarily using and, in turn, what physiological adaptations we’re targeting during that run.
But as most of our athletes train to complete a specific distance in a specific timeframe, how can heart rate really help? And at what point does the data start to interfere with our ability to listen to our body? When is it actually helpful to train by heart rate?
Let’s talk about it!
Why Train by Heart Rate?
∙ It shows how hard your body is really working.
∙ Pace can lie — heart rate tells the truth. HR reflects true effort.
∙ It helps athletes keep easy runs easy. This is our favorite way to utilize heart rate training. Most runners go too fast on recovery days. Heart rate training (especially in Zones 1–2) forces you to slow down and build a stronger aerobic base.
∙ Sick? Tired? Stressed? Your heart rate knows—even if your pace doesn’t. Training by HR helps you avoid overtraining and make smarter day-to-day choices.
Common Pitfalls of Heart Rate Training:
∙ Wrist-based monitors can lie.
∙ GPS watches often provide inaccurate readings, especially during high-intensity efforts or cold weather.
∙ Most watches estimate zones using only your age.
∙ That’s not accurate enough for effective training.
∙ Watch out for cardiac drift: Heat, caffeine, altitude, and stress can raise your heart rate without a true increase in effort. That’s why HR can climb over time even if your pace stays steady.
∙ Learning what each zone feels like is essential. Over-reliance on data can prevent athletes from developing body awareness and at the end of the day, we want our athletes to have that advantage during their races.
Getting Accurate Heart Rate Zones:
You need personalized zones for heart rate training to be useful!
How to find them ⤵️
✅ Best method: Functional Threshold Heart Rate (FTHR) test
✅ Backup method: Max HR from hill repeats or race efforts
❌ Worst method: Age-based guesses or default watch settings
Training Zones (Quick Guide):
∙ Zone 1 – Recovery Effort – 50–60% of Max HR
∙ Zone 2 – Endurance – 60–70% of Max HR
∙ Zone 3 – Aerobic – 70–80% of Max HR
∙ Zone 4 – Lactate Threshold – 80–90% of Max HR
∙ Zone 5 – VO₂ Max / Anaerobic – 90–100% of Max HR
Note: These percentages only work if we know the athlete’s true max heart rate or threshold HR.
Most Advantageous Method for Most?
∙ Heart rate + Rate of Perceived Exertion (RPE) = smarter, more intuitive training.
∙ Use RPE to build body awareness. On a scale of 0–10, ask yourself: How hard does this actually feel?
∙ Use heart rate when you (or your coach) question whether you’re going too hard—especially on easy days or in longer workouts.
∙ Over time, blend data with instinct to develop smarter pacing and better self-regulation.
At the end of the day heart rate training is another tool we can keep in our toolkit. It’s an awesome way to make sure we are accomplish what we’ve set out to accomplish on each run. However, developing the ability to know effort is important too. We recognize that learning effort can be more challenging as well due to it’s nuanced nature. We will always encourage our athletes to do what’s right for them!
References:
Seiler, S. & Tønnessen, E. (2009). Intervals, Thresholds, and Long Slow Distance: The Role of Intensity and Duration in Endurance Training. Sports Science.
Friel, J. (2016). The Triathlete’s Training Bible. VeloPress.
Coyle, E.F. (1995). Integration of the physiological factors determining endurance performance ability. Exercise and Sport Sciences Reviews.
Zinner, C. et al. (2015). Analysis of training intensity distribution in elite endurance athletes. Journal of Strength and Conditioning Research.
American College of Sports Medicine (ACSM). ACSM’s Guidelines for Exercise Testing and Prescription.
