22/04/2026
Three related questions (and pieces of advice) tend to come up again and again in slightly different forms. They’re hard to explain precisely because they’re built on a correct principle – implemented poorly:
• “Am I running at too high a heart rate?” / “How do I lower my heart rate while running?” / “You’re running at too high a heart rate.”
• “Most training should be in Zone 2.”
• “How should I set my zones on my watch?” / “Is it possible that my entire run is in Zone 5?”
The question about running at a “low heart rate” comes up frequently, and the fact that most of us wear heart rate monitors reinforces it. Heart rate is simple, measurable, and gives a sense of control. But from a physiological and training perspective, this is an imprecise interpretation of a valid concept.
It’s hard to overstate the importance of easy training. A large and consistent body of research shows that most improvements in aerobic capacity, especially in elite athletes, but also in recreational ones, are associated with a high volume of low-intensity work. Training at lower intensities is linked to increases in mitochondrial density and function, improved fat oxidation, and greater cardiovascular efficiency.
However, translating “easy training” into “low heart rate” is a problematic shortcut.
Heart rate is an indicator of intensity, not the intensity itself. It reflects physiological strain at a given moment, but it’s neither the only metric nor necessarily the most accurate one. Running pace, power output, breathing rate (for example, the “talk test”), and perceived exertion (RPE) are all valid measures of intensity. In practice, they should complement, if not sometimes replace, heart rate in assessing true intensity, both from an objective standpoint (external load) and a subjective one (internal physiological stress relative to the athlete’s capacity).
Heart rate is also highly individual. It’s influenced by age, s*x, genetics, fitness level, recovery status, temperature, hydration, sleep, stress, and even medications (such as beta-blockers). In other words, what counts as a “low heart rate” for one person might represent an easy effort, while for another it could be moderate or even high.
This gap becomes particularly evident in three populations:
• Beginners or athletes returning from injury or a break, whose aerobic systems are not yet well developed, so even easy efforts can produce relatively high heart rates.
• Individuals with atypical heart rate responses, whether naturally or due to medication.
• Well-trained athletes, whose physiological thresholds are high, so what’s labeled “Zone 2” is not necessarily easy at all.
So the goal is not a “low heart rate,” but a low-intensity effort.
In practice, that means running at an intensity where breathing remains comfortable, conversation is possible, and volume can accumulate without significant fatigue. Heart rate can be a useful tool, but only when it’s calibrated to the individual, not based on absolute values and formulas. Lowering heart rate should never be the goal in itself; rather, it’s a byproduct of improved aerobic fitness.
A key point to remember: aerobic fitness, reflected in a low resting heart rate (sometimes approaching 40 bpm or even lower) and relatively low heart rates during easy efforts, is not the result of targeted “low heart rate training.” It’s the inevitable outcome of years of consistent, high-volume training. Instead of trying to force heart rate down, the focus should be on consistent training over time. The heart rate will follow.
When using heart rate as a measure of intensity, it’s best to interpret it relative to the individual profile: athlete physiological profile as reflected by the 1st and 2nd ventilatory/lactate thresholds, lactate threshold heart rate (LTHR), zones determined through field or lab testing, or even consistent longitudinal analysis of training data. General formulas like “220 minus age” may serve as a rough starting point, but they are far too imprecise for managing training load and can lead to misleading conclusions.
Once we add structured zones, like “Zone 2 training”, we introduce another layer of confusion, largely because multiple zone models exist, and some (including the default settings in many sports watches) are not aligned with individual physiological differences.
The table below illustrates how heart rate zones can vary between athletes of different levels—and how they compare to typical watch-based zones:
(See Image)
A few key observations:
• The upper limit of Zone 1 rises significantly with fitness (from ~62% to ~75% of max HR). Elite athletes often perform easy runs at intensities their watch would label as “Zone 2.”
• Zone 3 (the Norwegian threshold zone) is where “double threshold” sessions take place. For professionals, it spans a wide range (80–90%), while for beginners it’s narrower and starts much lower.
• Default watch zones tend to underestimate Z1 and Z2 for trained runners. A truly easy run for an elite athlete (Z1) may appear as Z2 or even Z3 on the watch—potentially misleading less experienced runners into going too hard.
• Z4 and Z5 become compressed at the upper end in elite athletes because LT2 is very close to maximal heart rate, leaving little room above it.
Anchor points (approximate):
• LT1 (~1.5–2 mmol/L lactate):
o Beginners: ~62–65%
o Trained: ~70–73%
o Elite: ~76–80%
• LT2 (~3.5–5 mmol/L lactate):
o Beginners: ~76–80%
o Trained: ~84–87%
o Elite: ~89–93%
