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Heart Rate Training for Runners: A Complete Beginner's Guide

Running Science

Your running watch says 155 bpm.

Is that good?

Is it too high?

Should you slow down?

For a new runner, heart rate can seem like another number to worry about. Pace tells you how fast you are running. Distance tells you how far you have gone. Time tells you how long you have been out.

Heart rate seems different.

It is trying to tell you what is happening inside your body.

That makes it useful. But it also makes it easy to misunderstand.

Heart rate is not a perfect measure of running intensity, and there is no single set of heart-rate zones that works for every runner. Your heart rate changes with exercise intensity, but also with heat, hydration, fatigue, terrain, stress and other factors.

Used properly, however, heart rate can help you understand your training much better.

Here is how to start.

What Does Heart Rate Actually Tell You?

Your heart rate is the number of times your heart beats per minute.

During exercise, your muscles need more oxygen and nutrients. Your cardiovascular system responds by increasing blood flow, and heart rate rises as exercise intensity increases.

This makes heart rate useful for estimating how hard your cardiovascular system is working.

It is especially useful for aerobic training.

If you are running at a steady effort and your heart rate is relatively low, the cardiovascular demand is lower than when you are running hard and your heart rate is much higher.

But heart rate is not a direct measurement of running speed or effort.

Two runners can run at the same pace with different heart rates.

The same runner can run the same pace with different heart rates on different days.

That distinction becomes important when you start using heart rate to guide your training.

Resting Heart Rate vs Exercise Heart Rate

Before looking at training zones, it helps to separate two different measurements.

Resting heart rate is your heart rate when you are at rest.

Exercise heart rate is your heart rate while you are exercising.

Resting heart rate is often measured in the morning, before getting out of bed or after a period of quiet rest.

For many people, resting heart rate falls within a relatively stable personal range. It can also change with factors such as illness, stress, sleep, training load, alcohol, and other physiological conditions.

A single unusually high reading does not necessarily mean anything is wrong.

What matters more is the pattern.

If your resting heart rate is consistently elevated compared with your normal baseline and you also feel unusually tired or unwell, that is useful information to consider alongside the rest of your recovery.

Exercise heart rate behaves differently.

It rises as exercise intensity increases and generally falls again when exercise stops.

The relationship between heart rate and exercise intensity is useful, but it is not perfectly fixed. Research on long-distance runners has demonstrated meaningful day-to-day variation in submaximal heart rate, as well as changes associated with factors such as dehydration and competitive conditions.

In other words, your heart rate is a measurement of your current physiological state, not a permanent label attached to a particular pace.

What Is Maximum Heart Rate?

Maximum heart rate, often written as HRmax, is the highest heart rate you can reach during maximal effort.

It is commonly used to create heart-rate zones.

You have probably seen the formula:

220 minus your age

This is often presented as a way to calculate maximum heart rate.

The problem is that it is only a population-level prediction.

It does not tell you your actual maximum heart rate.

A widely cited study by Tanaka and colleagues proposed the equation:

208 minus 0.7 × age

based on a large sample of healthy adults.

But even this equation produces an estimate rather than an individual measurement.

Research specifically examining recreational marathon runners has also found substantial individual variation around age-predicted maximum heart rate equations.

So if a 30-year-old runner uses 220 minus age, they get an estimated HRmax of 190 bpm.

That does not mean their actual maximum heart rate is 190.

It could be higher.

It could be lower.

This matters because an error in your estimated maximum heart rate gets carried into every zone calculated from it.

For beginners, heart-rate zones based on a simple formula can therefore be useful as a rough starting point, but they should not be treated as laboratory measurements.

What Are Heart-Rate Zones?

Heart-rate zones are simply ranges used to describe different levels of exercise intensity.

You will often see five-zone systems:

Zone 1: Very easy

Zone 2: Easy to moderate

Zone 3: Moderate

Zone 4: Hard

Zone 5: Very hard to maximal

The exact heart-rate boundaries depend on how the zones were defined.

Some systems calculate zones as percentages of maximum heart rate.

Others use heart-rate reserve, which takes resting heart rate into account.

Others are based on physiological thresholds such as the first and second ventilatory thresholds or lactate-related measures.

This is where things get confusing.

Two apps can give you different zones for the same runner and both be following a legitimate methodology.

Research comparing methods of quantifying training intensity has shown that the resulting training distribution can differ depending on whether intensity is defined using heart rate, running speed, blood lactate, race pace or perceived exertion.

There is therefore no universal five-zone model that should be treated as the definitive version.

The important question is not:

"Which zone system is correct?"

It is:

"What physiological or practical definition does this zone system represent?"

Why Your Zones Are Not Universal

Imagine two runners.

Runner A has a maximum heart rate of 185 bpm.

Runner B has a maximum heart rate of 205 bpm.

If both are told that Zone 2 ends at 70% of HRmax, they will get very different absolute heart-rate values.

Even more importantly, their physiological thresholds may not occur at the same percentage of HRmax.

This is why percentages of maximum heart rate are useful approximations but not perfect physiological boundaries.

A 2022 paper proposing a simple approach to defining training intensity in endurance runners noted that the boundaries between intensity domains can be identified using different methods, including the talk test, perceived exertion, respiratory gas exchange, maximal lactate steady state and critical speed.

That is a more useful way to think about zones.

A zone is not just a number on your watch.

It represents a range of physiological demand.

For recreational runners, this distinction is particularly important because most training does not need laboratory precision.

You can often combine heart rate with pace and perceived effort to get a much better picture of intensity.

Zone 2 Is Not a Magic Number

"Zone 2" has become one of the most popular phrases in endurance training.

But it is also one of the most misunderstood.

Depending on the system being used, Zone 2 can refer to different physiological ranges.

In some systems it broadly corresponds to low-intensity aerobic exercise.

In others, the zone boundaries are calculated differently.

So telling someone to "run at 140 bpm because that is Zone 2" without knowing how that zone was established is not particularly meaningful.

For many recreational runners, a genuinely easy aerobic run will involve comfortable breathing and the ability to speak in sentences.

Heart rate can help confirm that intensity.

It should not replace basic observation of how the effort feels.

This is consistent with research suggesting that multiple methods of monitoring training intensity can complement one another rather than relying on a single metric.

Heat Changes Your Heart Rate

This is one of the most important things to understand about heart-rate training.

Suppose you normally run an easy 5 km at 6:30/km with a heart rate around 140 bpm.

Now run the same distance in hot, humid conditions.

Your pace might be slower.

Your heart rate might be higher.

That does not necessarily mean your fitness has suddenly deteriorated.

Your cardiovascular system is dealing with an additional thermoregulatory demand.

During prolonged exercise in the heat, heart rate can progressively increase while stroke volume decreases. This phenomenon is commonly called cardiovascular drift. Heat and dehydration can increase the magnitude of this response.

Research has also found an association between dehydration and increased heart rate during exercise in the heat. A systematic review found an average increase of approximately 3 beats per minute for each 1% of body-mass loss in the studies it examined, although individual responses varied.

This is why heart-rate targets should not be interpreted without considering the environment.

On a hot day, your normal easy-run heart rate may require a slower pace.

That is not a bad workout.

It is the appropriate response to the conditions.

Hills Change the Relationship Too

Heart rate also responds to terrain.

Run uphill and the metabolic cost of running increases.

If you try to maintain your flat-road pace, your heart rate will usually rise.

That does not mean you suddenly need to classify the run as a hard workout.

It means the terrain changed the demand.

This is why effort-based training can be particularly useful on hills.

If your training goal is an easy aerobic run, you may need to slow down uphill to keep the overall effort under control.

The same principle applies to trail running, where footing, gradients and technical terrain can make pace a poor representation of physiological intensity.

Heart rate gives you another way to understand the session.

Why Does Heart Rate Drift During Long Runs?

You start your long run.

For the first 30 minutes, you are running at 6:30/km and your heart rate is 140 bpm.

An hour later, you are still running at approximately 6:30/km.

Your heart rate is now 148.

What happened?

This is cardiovascular drift.

During prolonged exercise, heart rate can gradually increase even when external workload remains relatively constant. Research describes this as a progressive increase in heart rate accompanied by a reduction in stroke volume, particularly during prolonged moderate-intensity exercise.

Heat and dehydration can make the effect more pronounced.

But drift is not necessarily a sign that something has gone wrong.

Some increase in heart rate during prolonged exercise is a normal physiological response.

It becomes particularly useful when interpreting long runs.

If your pace remains constant but heart rate gradually climbs, that tells you something about the physiological cost of maintaining that pace over time.

If you are trying to keep heart rate constant instead, you may find yourself slowing down as the run progresses.

Both approaches can provide useful information.

Pace vs Heart Rate

This is where heart-rate training becomes most practical.

Pace and heart rate answer different questions.

Pace tells you what you are producing.

Heart rate tells you something about how your cardiovascular system is responding.

Suppose your training plan says to run an easy session.

Your normal pace is 6:20/km.

Today it is 30°C and humid.

At 6:20/km, your heart rate is much higher than usual and the run feels harder.

Holding the pace simply because the number appears in your training plan may turn an easy session into a harder one.

Slowing down allows you to preserve the intended training intensity.

Now consider an interval session.

Your workout calls for 5 × 1 km at a particular pace.

Here, pace may be more useful because the workout is designed around a specific running speed.

Heart rate has a delay. It does not instantly respond to changes in intensity, particularly during short intervals.

That makes heart rate less useful for controlling the first few seconds of a short repetition.

It can still provide useful information about the overall session.

This is why different workouts benefit from different controls.

For an easy run, heart rate and perceived effort can be useful guides.

For a short interval, pace may be more practical.

For a long run, the combination of pace, heart rate and effort can tell you much more than any single metric.

How Should a Beginner Actually Use Heart Rate?

You do not need to make your running complicated.

Start by establishing your normal range.

Wear your heart-rate monitor consistently.

Record your heart rate during easy runs.

Notice how it changes with pace.

Notice what happens on hills.

Notice what happens in hot weather.

Notice how it responds when you are tired.

Over time, you will begin to understand your own data.

That is more valuable than memorizing someone else's perfect zone.

For most beginners, a simple framework works well:

Easy runs: Keep the effort comfortable. Use heart rate as a guide rather than chasing an exact number.

Long runs: Keep intensity controlled early. Watch how heart rate and effort change as the run progresses.

Quality sessions: Use the workout's prescribed pace or effort when appropriate. Do not expect heart rate to respond instantly to short intervals.

Hot days: Expect heart rate to be higher or pace to be slower at the same effort.

Hilly routes: Let pace change with terrain if the goal is to maintain a consistent effort.

Fatigued days: Interpret heart rate alongside how you feel rather than treating the number as an absolute instruction.

Heart Rate Is a Tool, Not a Judge

The biggest mistake with heart-rate training is treating your watch as if it knows exactly how hard you should run.

It does not.

Your heart rate is one piece of information.

Pace is another.

Perceived effort is another.

The environment provides context.

Your training history provides more.

Put them together and the picture becomes much clearer.

A runner who understands heart rate does not panic because today's pace is slower.

They ask why.

Maybe it is hot.

Maybe there is a hill.

Maybe they are carrying fatigue.

Maybe their heart rate is responding normally to a long run.

Or maybe the effort really is higher than it should be.

That is the real value of heart-rate training.

It is not about finding one perfect number.

It is about learning to understand the relationship between your pace, your body and the conditions around you.

Once you can do that, the number on your wrist becomes much more useful.

References

1. Seiler, S. (2010). What Is Best Practice for Training Intensity and Duration Distribution in Endurance Athletes? International Journal of Sports Physiology and Performance.
2. Sylta, Ø., Tønnessen, E., Hammarström, D., Danielsen, J., Skovereng, K., Ravn, T., Rønnestad, B. R., Sandbakk, Ø., & Seiler, S. (2022). A Simple Approach to Defining Training Intensity in Endurance Runners. International Journal of Sports Physiology and Performance.
3. Kenneally, M., Casado, A., & Santos-Concejero, J. (2021). The Effect of Training Intensity Distribution on Middle- and Long-Distance Running Performance: A Systematic Review. International Journal of Sports Physiology and Performance.
4. Tanaka, H., Monahan, K. D., & Seals, D. R. (2001). Age-Predicted Maximal Heart Rate Revisited. Journal of the American College of Cardiology.
5. Nikolaidis, P. T., et al. (2018). Age-Predicted Maximal Heart Rate in Recreational Marathon Runners: A Cross-Sectional Study on Fox's and Tanaka's Equations. Frontiers in Physiology.
6. Wingo, J. E., Ganio, M. S., & Cureton, K. J. (2012). Cardiovascular Drift During Heat Stress: Implications for Exercise Prescription. Exercise and Sport Sciences Reviews.
7. Coyle, E. F., & González-Alonso, J. (2001). Cardiovascular Drift During Prolonged Exercise: New Perspectives. Exercise and Sport Sciences Reviews.
8. Adams, W. M., Ferraro, E. M., Huggins, R. A., & Casa, D. J. (2014). Influence of Body Mass Loss on Changes in Heart Rate During Exercise in the Heat: A Systematic Review. Journal of Strength and Conditioning Research.
9. Achten, J., & Jeukendrup, A. E. (2003). Heart Rate Monitoring: Applications and Limitations. Sports Medicine.