January 19, 2025, 3:53 pm | Read time: 9 minutes

Many people are probably familiar with the problem: both strength and endurance training are complex matters. If you simply start training without a plan, you will probably not achieve your performance goal. With endurance training, in particular, it is important to pay attention to so-called training zones or training areas. FITBOOK explains the training zones and why you should train in zone 2 in particular.

The Five Training Zones and What They Are Good for

Training zones are defined as certain heart rate ranges between resting and maximum physical exertion.

Zone 1

Very light training takes place at 50 to 60 percent of the maximum heart rate, serves general health, and helps with regeneration.

Zone 2

Light training, performed at 60 to 70 percent of maximum heart rate, improves general endurance and helps to tap body fat as an energy source.

Zone 3

Challenging exercise, performed at 70 to 80 percent of maximum heart rate, increases aerobic fitness.

Zone 4

Hard training, performed at 80 to 90 percent of maximum heart rate, increases speed endurance and uses carbohydrates for energy.

Zone 5

Very hard training, performed at 90 to 100 percent of maximum heart rate, improves maximum performance.

How to Determine Your Heart Rate

Although heart rate, heartbeat, and pulse are, strictly speaking, different terms, they are often used as synonyms. For example, the heart rate also corresponds to the pulse rate, which is measured on the wrist with a heart rate monitor. This is because the throbbing of the blood on the vessel walls caused by the heartbeat is referred to as the “pulse”^.1

The pulse is very individual for each person and depends not only on genetic predisposition, gender, and age but also on the level of training. In untrained people, the resting pulse rate can be between 60 and 100 beats per minute. In trained endurance athletes, the heart muscle is larger and stronger, which means that more blood is pumped per beat. This results in a lower heart rate, which can be between 40 and 50 beats per minute, and even lower for elite marathon runners, as our expert confirms.

Four Methods to Measure Your Pulse

1. Measure your pulse on your wrist: For example, by pressing your right index finger against the artery on your left wrist, you can feel the pulse in the artery. Count the pulse beats within 15 seconds and multiply by four to obtain the pulse value.
2. Measure the pulse at the neck: Similar to the wrist measurement, except that you count the beats on the carotid artery (below the lower jaw at ear level).
3. Measuring the pulse at the heart: To do this, place your hand on your heart and count the beats in the same way as methods one and two.
4. Measuring with a heart rate monitor: Heart rate monitors on the wrist or heart rate belts enable continuous measurement even during training. Chest straps are more precise than sensors on fitness trackers and smartwatches, which use light-sensitive photodiodes.

How Do You Find out Your Maximum Heart Rate (HRmax)?

The maximum heart rate is achieved with the greatest possible physical exertion. This value is also called “HRmax,” which is given in heartbeats per minute and corresponds to the pulse. Like the resting heart rate, the maximum heart rate also depends on age, gender, genetic predisposition, and personal training status. In contrast to the resting heart rate, determining the maximum heart rate is somewhat more complex. Although there are various formulas that can be used to determine the “HRmax,” as these do not take personal predisposition into account, they only ever provide an estimated value. In this respect, the following two methods are much more accurate.

Determine HRmax with a Sports Medicine Examination

If you want to know exactly, it’s best to have a performance test carried out by a sports doctor. “This is the sole method for pinpointing the precise HRmax value,” clarifies sports physician Enrico Zessin. Here, not only the individual heart rate ranges are measured, but also the lactate levels in the blood. For example, you know exactly at what heart rate your muscles become over-acidified. The test is also carried out under medical supervision. This supervision is important for untrained people and those who are very overweight.

Determine Your Maximum Heart Rate with a Self-Test

If you have already trained and pushed yourself to your limits without any health problems, you can also carry out a self-test. This is best done while running or on a home trainer (ergometer) with a heart rate monitor on your wrist or with a chest strap (chest straps are generally more accurate).

The Test Is Carried Out as Follows:

1. First, you warm up for at least ten minutes at a relaxed pace.
2. Then, you increase your speed within three minutes. The first minute is at a relaxed pace, the second minute is towards your performance limit, and the third minute is at your absolute maximum performance level.
3. Do not stop immediately afterward, but actively recover at a relaxed pace.

The heart rate determined at the limit corresponds to the maximum heart rate. For certainty, it’s advisable to repeat the three-minute test two additional times.

Why Zone 2 Training Is So Important

Especially amateur athletes frequently underestimate the importance of light ‘Zone 2’ training. They prefer to exercise in the strenuous training zones three and four. They feel they are pushing their body harder and, therefore, doing more for their performance. However, consistently pushing oneself to the limit risks excessive exhaustion of the body. “The training effect is then only moderate, as the circulation and muscles are always working at a slightly overloaded level, meaning that only a slight adaptation or increase in performance is possible,” says sports physician Zessin.

With “Zone 2” training, you work in the area of basic endurance (GA), i.e., with a moderate circulatory load over a longer period of time, explains the expert. This takes place in the area of aerobic metabolism, where fat burning is mainly used to generate energy. It serves as the basis for almost all types of sports but is particularly important in endurance and ball sports. This training not only strengthens the body but also increases cardiovascular performance. It also optimizes the (muscle) metabolism. Even speed is trained by building on the basic endurance through further intensive training units.

“Basic endurance forms the foundation, so you can say that you can only get faster if you train slowly,” says Enrico Zessin.

How Much Zone 2 Training Is Ideal?

Ultimately, it’s about making your training as varied as possible. Many athletes, therefore, adhere to the 80/20 rule. This means that they spend 80 percent of their training in zone 2 and 20 percent on (high) intensity units.

Expert Enrico Zessin recommends zone 2 training two to three times a week for at least 45 to 60 minutes (or longer).

Five Good Reasons to Train More Often in Zone 2

Low Intensity

The low intensity of Zone 2 training makes it ideal for preparing the body for intensive training sessions or for recovering from them.

Increase in Endurance

Zone 2 training increases endurance. If you exercise at 60 to 70 percent of your maximum heart rate, you can easily train for one to two hours and talk to a training partner, for example.

Boosting Fat Burning

In zone 2, you boost fat burning. This not only gets rid of fat deposits but also gets the body used to activating the fat metabolism more often. This is very important for marathons, for example, in order to conserve carbohydrate stores, says Zessin.

Health-Promoting

Zone 2 training is particularly beneficial to health and can even contribute to a longer life. People who exercise more often for one to two hours at a low intensity lower their blood pressure and resting heart rate, strengthen their blood vessels, and have a healthier metabolism and better immune system. In addition, the number of mitochondria and their effectiveness increases. These are the power plants in the cells of our body that are used to generate energy. The better they function, the more they protect against diabetes, for example. As Enrico Zessin confirms, Zone 2 training can protect against obesity, high blood pressure, metabolic diseases such as diabetes, heart and lung diseases, and even cancer.

Improving Quality of Life

All the positive health effects ensure an increase in the general quality of life into old age.

How Do You Know If You Are Training in Zone 2 Without a Heart Rate Monitor?

If you don’t know your HRmax and can’t correctly classify where 60 to 70 percent of your maximum heart rate lies, you should pay attention to your body, the effort you feel, and, above all, your breathing. Even without a heart rate monitor, you can feel whether you are in zone 2 or already above it. For example, runners should be able to talk to a training partner without too much effort. The effort feels manageable, creating a sensation that one could continue running for hours. You are in a kind of “flow,” a rhythm of movement in which you hardly feel the muscle contraction.

If you start to breathe more deeply, find it difficult to talk, and can feel your muscles at work, you are already in zone 3. However, if you feel under-challenged and find training too easy, you are probably in zone 1. In other words, training in zone 2 feels like the sweet spot between effort and relaxation – you simply feel good doing it.

More on the topic

For basic fitness This is how long and fast men and women should be able to run

For basic fitness How long men and women should be able to swim

For basic fitness This is how long and far women and men should be able to cycle

The Problem with Training by Zone

Training based on heart rate or the corresponding training zones is subject to strong daily fluctuations of up to 15 beats per minute. “Various factors have an influence: sleep, stress, diet – whether you exercise on an empty stomach, for example – the time of day, a mild infection, the outside temperature, etc. This means that the personally defined training zones can easily shift,” explains Enrico Zessin.

Particularly for ambitious athletes, metrics such as pace for running or wattage for cycling and rowing are thus far more appropriate for managing training. For this reason, determining the performance ranges to create training recommendations using performance diagnostics only makes sense for some athletes.