Many people who engage in running or other forms of cardio training often use a heart rate monitor. These heart rate monitors provide a display of the heart rate during exercise. But why is that important? And what is a good heart rate during exercise, and when is it too high or even dangerous? You’ll find out here.
Why Cardio Fitness
The goal of cardio fitness is often focused on improving overall fitness and endurance. This form of training is also often called cardio training or endurance sports and can be performed at various intensities.
Due to these intensities, as well as the duration of the workouts, the goals can vary greatly. It is therefore important to keep track of your heart rate to determine if you are training at the intensity that matches your goal.
Measuring Your Heart Rate
Okay, so cardio fitness and heart rate are closely linked. But how do you measure your heart rate? In principle, you can measure your heart rate quite easily without a heart rate monitor. You can do this perfectly with your regular watch or with a clock.
Place your finger against your pulse in your neck and then count the number of times you feel your heart rate beating for 1 minute. The number of times you feel your heart rate in that one minute is your heart rate per minute.
If you have measured your heart rate over 30 seconds, you can also multiply the result by 2 to calculate your heart rate per minute.
The same applies in principle after 15 seconds. Then you multiply your heart rate by 4 to calculate your heart rate per minute.
This method is of course somewhat less practical during exercise, which is why many people wear watches with heart rate monitors. With these, you can read your heart rate on your wrist.
You can also measure your heart rate by wearing a heart rate monitor. You often strap this around your chest, using a strap, and you can measure your heart rate on the device you are training on.
What is a Healthy Resting Heart Rate?
As many people, so many different heart rates you could say. Let me immediately clarify that the heart rate can vary greatly from person to person and depends on many factors.
So, there is no single healthy heart rate.
Age is one of the most important factors that determines your heart rate, and your gender also plays a significant role.
If you have a lot of stress, drink a lot of coffee, or smoke a lot, your heart rate is often much higher.
On average, the resting heart rate is between 60 and 80 beats per minute in men, and in women, it is often slightly higher. When you go to sleep, your heart rate drops back to around 50 beats per minute.
If you want to know how your heart rate develops during your sleep, you can easily measure this by wearing an Apple Watch.
Heart Rate Zones
If the goals of your cardio training mainly focus on improving your fitness, then your heart rate should be between 75 and 90 percent of your maximum heart rate. You can easily calculate this using the following formula:
Maximum heart rate: 220 – your age in years.
So, someone who is 20 years old has a maximum heart rate of 200, according to this formula. This means that if he wants to train his fitness, his heart rate should be between 150 and 180.
Many factors influence your heart rate, including heredity and your own basic fitness. That is why this formula is an estimate and never 100 percent accurate.
If you want to use the same formula for your cardio training for fat burning goals, then your heart rate should be lower, somewhere between 55 percent and 75 percent. This is often called the aerobic training, and in this, the body mainly uses fatty acids as energy sources.
Heart Rate Formulas
Because your heart rate can change due to cardio training, it is important to first determine what your resting heart rate is. As mentioned above, your resting heart rate is the heart rate at rest.
When your fitness improves, your resting heart rate becomes lower. Some people have a resting heart rate of 30 beats per minute, but there are also cases where the resting heart rate can be around 100. If you have a heart rate above 90, this may indicate overtraining or an illness.
To determine the resting heart rate, do it in the morning, just after you wake up, and actually measure it by measuring the number of beats in 1 minute. If you want to measure your resting heart rate very accurately, do 3 measurements on 3 different days and take the average.
With the Karvonen formula, you can determine your training intensity using your maximum heart rate and your resting heart rate. The Karvonen formula is as follows:
Heart Rate Zone = (Maximum Heart Rate – Resting Heart Rate) * ..% + Resting Heart Rate (+5 Sun -5)
In the Karvonen formula, you start from the difference between your maximum heart rate, which you have been able to measure based on your age, and your resting heart rate, which you have measured for 3 mornings in a row. The difference between these two is your heart rate range. When you add a percentage to this, the different heart rate zones become clear to you, and you know at what heart rate you should train.
A Good Heart Rate During Exercise
Now that you know what your resting heart rate means and how to calculate your maximum heart rate, we can look at what a good heart rate could be during exercise.
You can divide your heart rate into 5 different heart rate zones. These are calculated based on your maximum heart rate.
Heart Rate Zone 1: Warm-Up
The intensity of heart rate zone 1 is 50% to 60% of your maximum heart rate and can be used for your warm-up or for cooling down. You often achieve this by walking slowly or jogging very lightly. You should genuinely feel a light exertion during this effort. This zone is also called the aerobic zone.
If you have good fitness or often run, you will find that you can run faster in this heart rate zone.
Heart Rate Zone 2: Fat Burning and Basic Fitness
The second heart rate zone is the fat-burning zone and is between 60% and 70% of your maximum heart rate. During training in this zone, you will notice that the effort becomes slightly more intense. You will notice that you are clearly exerting yourself, but the training should still feel easy and pleasant. Your breathing will be slightly shorter, but you should still be able to have a conversation.
You can often maintain this pace for a long time without getting cramps or your muscles acidifying, making it a very good zone if you have fat burning as a goal.
Heart Rate Zone 3: Improving General Training Pace
If you train in heart rate zone 3, you train at 70% to 80% of your maximum heart rate. Training in this heart rate zone requires more effort, and you will notice that you are more out of breath than in the previous 2 zones. You should still be able to have a conversation, but it will be less straightforward. If you train in this heart rate zone, you mainly want to improve your performance for a competition.
Heart Rate Zone 4: Sustaining High Speed
The fourth zone is between 80% and 90% of your maximum heart rate and is a lot more challenging. When training in heart rate zone 4, you will breathe harder, and you will also produce more lactic acid. The training in zone 4 is also called the anaerobic phase.
If you train in zone 4, you often want to improve your fitness. Because you cannot sustain the training in this zone for long, the training in this zone is often interval training, alternating 2 minutes of effort with rest.
Heart Rate Zone 5: Maximum Effort
This is the most intense heart rate zone, where you train up to 100% of your maximum heart rate. You will not be able to sustain the training in this zone for long, and you will quickly become out of breath.
Training in heart rate zone 5 is often intended for trained athletes, in the final phase towards a competition.
Generally, up to 80% of your maximum heart rate is sufficient to make progress and improve your overall fitness. You burn more calories when your heart rate is higher, but of course, you also need to sustain it for a long time.
Training at your maximum heart rate is not recommended because it can be dangerous, and you will not be able to sustain it for long. After all, your heart contracts and pumps blood through your entire body via the blood vessels, and if you do this at your maximum heart rate, it can become dangerous.
If you still want to train above 80% of your maximum heart rate, do so under professional supervision.
Fat Burning Zone
Heart rate zone 2 was already indicated above as the fat-burning zone. People who want to lose weight are often advised to train in this heart rate zone.
This works as follows: when you are training, your body gets its energy from various sources. After all, your body knows various energy systems:
1. ATP-CP system / phosphate system
2. The Anaerobic system / lactic acid system
3. The Aerobic system
When you train in heart rate zone 2, your body gets the required energy from carbohydrates and from glucose and some from body fat. In this zone, your body consumes relatively more fat and fewer carbohydrates than in the other heart rate zones with a higher heart rate.
Conclusion: What Is a Good Heart Rate During Exercise?
Anything below 80% is fine to work on your fitness and fat burning. Training in higher heart rate zones is not recommended because it can be harmful and dangerous for the heart.
A lot of stress hormone, cortisol, is also released above 80%.
The Dutch Heart Foundation therefore advises to build up slowly when you are just starting out and not to go higher than 50% of your maximum heart rate in the first few weeks. And then build it up to 80% of your maximum heart rate.
