Runner's heart rate, what does it actually mean?

A heart rate monitor is an increasingly popular device supporting training . It allows us to measure heart rate during training. Often it is a band worn on the chest, from which the measurement can be read on a wrist watch. Sometimes we have a built-in heart rate sensor in the watch placed on the wrist with readings from the watch.

Electronics for runners offer more and more functions, those related to heart rate, but also additional functions related to the built-in GPS, temperature sensor and barometer. However, we want to focus on measuring the heart rate. Most good quality watches available on the market give us the option of displaying our heart rate in beats per minute or as a percentage.

Here a question may arise from a beginner runner: "But what exactly do these percentages mean?" We will explain this issue in a moment and consider whether it is worth trusting such conversions into percentages or not.

At the very beginning, you will need to know a few concepts:

Maximum heart rate (Hr _max ) - this is the rate of heart beats per minute at the moment of maximum effort, so it is very difficult to determine precisely. This is not a parameter that we are able to "train", its value is therefore not strictly related to the level of our fitness, but to genetics.

We can determine such a heart rate empirically, i.e. during very intense physical exertion, often e.g. by reading the measurement from a heart rate monitor when running to the finish line after a sprint, or by preparing a special test during which we exercise (depending on the discipline practiced) to the maximum of our capabilities.

As you can see, determining such a heart rate is not easy and not everyone wants to try such experiments. You can also use ready-made formulas to calculate such a value, but remember that these formulas are generalizations and will only work relatively accurately for a certain group of people, and the calculations have a large margin of error. The most popular patterns are:

For women: HR _max = 226 - age
For men: HR _max = 220 - age

This result is very approximate to our actual maximum heart rate and, as you can see, it depends only on the age and gender of the person. An interesting formula that also takes into account the weight of the subject, making it more accurate and more individualized, is as follows (Sally Edwards formula):

For women: Hr _max = 210 - 0.5 x age – 0.022 x weight [kg]
For men: Hr _max = 210 - 0.5 x age – 0.022 x weight [kg] + 4

There are many other formulas that allow us to calculate the maximum heart rate, but you should be aware that these are only estimated values, more or less accurate, but they are very helpful in further work with the heart rate and the heart rate monitor.

Example: woman, 30 years old, weight 58 kg

Method 1: Hr _max = 226 - 30 = 196
2nd method (Sally Edwards formula): Hr _max = 210 - 0.5 x 30 – 0.022 x 58 = 194

As you can see, it turns out that the difference in calculations is 3 beats/min.

Resting heart rate (Hr _rest ) - [more: Resting heart rate, what it says about your fitness ]

Heart rate reserve (HRR) - this is the difference between the maximum heart rate (Hrmax) and the resting heart rate (Hrrest). It is the basis for further calculations of heart rate energy zones and illustrates the range of heart rate changes depending on exercise intensity.

HR _R = HR _max - HR _rest

Having collected the basic parameters: maximum heart rate, resting heart rate, heart rate reserve, we can calculate our individual percentage zones.

The simplest way to do this is to determine the percentage value by calculating it as a percentage of the maximum heart rate, e.g. for exercises with an intensity of 70%HR _max

70%: 0.7 x HR _max

Similarly, we determine other percentage values: 65%, 60%, etc. by replacing "0.7" in the formula with the appropriate fraction.

This is a very simple way to quickly calculate these values, but it is also not very accurate. Statistically, it works for 4 out of 10 athletes, more often it will be correct for beginners and amateurs, and increasingly different from the actual parameters for trained people and professionals.

Here, a more accurate method comes to our aid - the Karvonen method, in which we use the calculated heart rate reserve, i.e. the resting heart rate is taken into account, which shows us the training level of a specific individual. This greatly improves the accuracy of calculations and, consequently, the work with heart rate during training.

70%: (0.7 x Hr _R ) + Hr _rest

Similarly, we determine other percentage values: 65%, 60%, etc. by replacing "0.7" in the formula with the appropriate fraction.

Example:

Hr _max = 194 Hr _rest = 68 Hr _R = 126

1 method: 80% = 0.8 x 194 = 155
2 method (Karvonen method) 80% = (0.8 x 126) + 68 = 168

You can see that the difference in this case is quite significant. This is largely influenced by the relatively low resting heart rate, which indicates the high level of training of the examined person. Therefore, it is worth collecting and using as many parameters as possible in the calculations, which allows us to individualize the final result.

This is how percentages are calculated, which are often given to us by watches or which we can calculate and control ourselves. Depending on the level of advancement of the watch, various calculation methods will be used. The more parameters we enter into the device, the more accurate the final calculated result. It is worth trying to calculate your heart rate values yourself and write them down.

Gosia Jurczak