How to use HRmax in your training?

What is HRmax?

HRmax, or maximum heart rate, is the value that can be reached during the most intense exercise. It reflects how efficiently your heart and circulatory system deliver oxygen to your muscles and remove metabolic waste. This efficiency determines how hard you can train and for how long. Based on HRmax, training zones have been created. Most heart rate monitors and sports apps use these zones to help you match your training to your goals:

• Zone 1: up to 60% HRmax – easy breathing, very light muscle work.

Suggested exercises: warm-ups and active recovery.

• Zone 2: 60-70% HRmax – comfortable breathing, moderate effort.

Suggested exercises: easy endurance training and fat burning.

• Zone 3: 70-80% HRmax – breathing becomes harder, muscles start to tire.

Suggested exercises: building aerobic endurance.

• Zone 4: 80-90% HRmax – heavy breathing, fast muscle fatigue.

Suggested exercises: threshold power training (aerobic/lactate threshold).

• Zone 5: over 90% HRmax – very heavy breathing, strong fatigue and discomfort.

Suggested exercises: short, intense anaerobic intervals with maximum power and pace.

Training with heart rate zones helps you exercise more consciously and in line with your goals. For beginners, the priority is usually building an aerobic base, meaning the body’s ability to work efficiently at a basic endurance level in Zones 2 and 3. More advanced athletes, focused on increasing performance capacity (for example during sprint running or steep cycling climbs), may need training that includes Zones 4 and 5. In both cases, the first step is determining individual maximum heart rate, which is then used to define personal training zones.

How do you calculate your maximum heart rate?

In the age of smartphones and smartwatches, this is very simple. During device setup, you enter personal details such as sex, age and weight, and the system automatically calculates maximum heart rate and training zones. But how does the device “know” how to calculate HRmax? It depends on which formula is used by the software.

The simplest and still most popular formula is the Haskell and Fox formula, developed in the 1970s:

            HRmax = 220 - age

This simple equation has been (and still is) the basic method for calculating maximum heart rate. It has been used by many coaches, athletes and heart rate monitor manufacturers. However, it is not very accurate. It is based on existing data sets rather than direct scientific research, and it does not account for individual differences. It also assumes a linear decline of HRmax with age, which is not the case. As a result, the standard deviation can be as high as 15 beats per minute.

Later generations of researchers and coaches analysed the issue in more depth, modifying the Haskell and Fox formula and adding extra factors such as sex, body weight and fitness level. Some of the most popular and slightly more accurate methods for calculating HRmax include:

Tanaka's formula:

• Women: 207.2 - 0.65 x age
• Men: 209.6 - 0.72 x age
• Trained individuals: 205 - 0.6 x age
• Untrained or occasionally active individuals: 212 - 0.7 x age

Edwards formula:

• Women = 210 - (0.5 x age) - (0.022 x body weight in kg)

• Men = 210 - (0.5 x age) - (0.022 x body weight in kg) + 4

A separate mention should be given to the Karvonen method, which is based on the Haskell and Fox formula but modifies it by including resting heart rate (HRrest). It also focuses on defining training zones. To use this method, you need to:

• Calculate HRmax according to the formula 220 - age.
• Determine resting heart rate (HRrest), for example by measuring it immediately after waking up.
• Define training intensity (in %) according to your training goals.
• Calculate target heart rate using the formula:

HRrest + intensity x (HRmax - HRrest).

Regardless of the chosen method, it is important to remember that HRmax is not always a fully accurate indicator of exercise intensity or fitness level. This metric has certain limitations that can affect precision in individual training.

What HRmax DOES NOT tell us – errors, myths and misunderstandings

The main issue with HRmax is that it works best in studies of large populations and in statistical measurement formulas. On an individual level, however, it is far less precise. Two people of the same age and sex, with similar body weight and fitness level, may have very different HRmax values. Maximum heart rate can be influenced by body composition, health status, circulatory system efficiency, height or the type of sport practised. In addition, heart rate measurements during “heart rate-based” training do not reflect specific training conditions, such as climbs, headwinds or tailwinds, or daily readiness factors like stress, body temperature or health. Even the most accurate HRmax value still does not account for all factors affecting heart function at the moment of measurement.

Another common misunderstanding related to training with HRmax percentages concerns effort intensity. Beginner athletes often treat average heart rate from a workout as a measure of fitness or training effectiveness. In reality, a heart rate monitor does not measure these values at all. For that purpose, power measurement is used, as it provides real-time insight into actual effort intensity. For example, an average heart rate of 150 beats per minute does not include crucial data such as generated watts, pace, duration or the type of workout performed – whether it was volume-based or interval training. Similarly, a higher instantaneous heart rate does not necessarily mean a better workout. The percentage of HRmax during exercise should match the goal of the session, not the other way around.

It is also worth noting that HRmax can vary depending on the sport. This is related both to training level and to the involvement of different muscle groups. 75% percent of HRmax while cycling is not the same as 75% during running or swimming. Conscious training requires taking this into account.

If not a heart rate monitor, then what?

Although heart rate monitoring is the most popular way to train cardio more consciously, it is still not the most accurate method. Modern smartwatches and fitness bands are becoming increasingly precise, and their optical sensors can provide readings close to those from chest straps. However, they are still limited by the imperfections of HRmax itself and the methods used to calculate it. Despite these limitations, HRmax provides a basic understanding of whether effort matches training goals and whether planned training loads are not being exceeded. It also increases body awareness – not only do we see values such as the aerobic threshold, but we also begin to feel when the body is approaching it. For beginners and intermediate athletes, this is very helpful, which is why training with a heart rate monitor is often recommended. Many cardio class instructors (for example in spinning classes) even require participants to use one.

For advanced athletes who are curious and have a larger sports budget, more precise effort-monitoring methods are recommended. These include performance tests, which provide a full overview of physiological parameters and allow very accurate measurement of key factors for a given discipline. They involve costs and need to be repeated according to training cycles, but at higher performance levels and when competing, they increasingly become a routine part of training plans.

If even greater precision is needed during training or competitions, power measurement is worth considering. Until recently, such devices were mainly associated with cycling, but they have now become popular in disciplines such as running and swimming as well. When paired with advanced apps and training diaries, they become a highly precise source of data about the athlete and for the athlete. Importantly, their reliability does not depend on additional factors in the same way as HRmax-based measurements. However, this level of accuracy comes at a price – and although it is lower than it used to be, it is still not a cheap investment!

^References:

^{1. Friel J., The Cyclist’s Training Bible, VeloPress, 2009.}

^{2. Górski J., Fizjologiczne podstawy wysiłku fizycznego, Warszawa, 2006.}

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^{4. Karvonen J., Vuorimaa T., Heart rate and exercise intensity during sports activities. Practical application, Sports Medicine, 1988.}

^{5. Berglund I. J., Relling B. E., Kiel I. A. i inni, The relationship between maximum heart rate in a cardiorespiratory fitness test and in a maximum heart rate test, Journal of Science and Medicine in Sport, 2019.}

^{6. https://journals.viamedica.pl/folia_cardiologica/article/view/92507}

^{7. https://www.researchgate.net/publication/221872127_Age-predicted_maximal_heart_rate_in_healthy_subjects_The_HUNT_Fitness_Study Dostęp do strony www: 12.12.2025}

^{8. https://www.nytimes.com/2001/04/24/health/maximum-heart-rate-theory-is-challenged.html}