Heart rate: what it is and what are the normal values

We often talk about heart rate in sports, because it is a useful parameter both to establish the correct intensity of physical effort, making it effective but not dangerous, and to monitor over time the effects it has on the body. But, beyond sport, knowing your heart rate serves everyone in life for cardiovascular prevention; It is, in fact, the easiest way to control any arrhythmias and understand when it is appropriate to seek the advice of your doctor.

So let’s see together what we mean when we talk about heart rate, how to measure it and the anomalies not to be underestimated.

What is it

Heart rate is defined as the number of beats that the heart makes in a minute or bpm (beats per minute). With each beat (or pulse), the heart muscle contracts to pump blood throughout the body.

Be careful not to confuse heart rate and blood pressure (although there is a relationship between the two): blood pressure derives from the force that the heart gives to the blood at each pulsation, but represents the push that the blood, or, more properly, blood flow, exerts on the walls of arterial blood vessels as it flows inside them. Heart rate, on the other hand, only indicates the amount of beats per minute.

The frequency varies naturally depending on the age and activity that is taking place, both physical training.

Heart rate can be measured at different times; Let’s see together when:

• at rest, which corresponds to the number of pulsations (per minute) of the heart under conditions of physical inactivity;
• maximum, i.e. the maximum value of beats per minute reachable by the heart under stress;
• recovery, which corresponds to the value that reaches the heartbeat two minutes after stopping exercise.

There are also pathological conditions that increase, decrease or alter the frequency of heartbeats with more or less serious consequences.

What are the normal values

Speaking of basic or resting heart rate, compared to different ages, the following values of pulse per minute are to be considered normal:

Factors affecting heart rate

As already mentioned, physiological variations in heart rate occur according to the age of the subject. However, there are other factors that contribute to changing the pulse rate and can affect its measurement. Among others we remember:

• ambient temperature and humidity (heat and humidity increase heart rate, both resting and maximum);
• body weight (generally those who are overweight have a higher heart rate);
• certain physical conditions or conditions such as arrhythmia, or an altered psychological state (including strong emotions or continuous anxiety);
• feeding, since a consumption of carbonated or exciting drinks causes the frequency to increase; In addition, according to recent studies, even a diet too high in sugar seems to be able to increase heart rate.

The frequency also varies depending on the time of day (at night, during sleep, for example, it is lowered, while getting up after eating), but also stress, sudden emotion (remember that the heart rate is under the control of the nervous system) and, above all, physical activity cause an increase in beats completely physiological.

For this reason, the values should be measured at rest: in this case, on average the heart rate of a man is about 70 bpm and about 75 bpm in women (except for trained athletes who almost always have a lower pace), while in newborns the resting frequency is about 130-150 bpm.

When the heart rate falls below the minimum values considered normal, we speak of bradycardia, while tachycardia is defined as the situation in which values above the maximum values are found for each age.

How to measure resting heart rate

Resting heart rate is typically measured by counting the beats you can hear on your wrist, although this method is not very accurate.

Here are 4 simple steps to measure your pulse on your wrist:

1. Sit at least 5 minutes before measuring the pulse; In addition, it is good to avoid taking stimulants such as coffee and nicotine immediately before the measurement, because they alter the heart rhythm. The ideal would be to do the measurement in the morning, as soon as you wake up.
2. Hold one of the two hands with the palm facing up and the elbow slightly bent.
3. With the other hand, place your index and middle finger on your wrist, at the base of your thumb. To be precise, the fingers must be between the bone that is located on the edge of the wrist and the tendon connected to the thumb. If you do not feel the pulse, it is advisable to move your fingers slightly. Then, keep them still by pressing to feel the heartbeat: keep your finger lightly pressed on the wrist, but without exerting excessive force;
4. Count the pulse for 30 seconds and multiply by 2 to get the heart rate of one minute. If, however, the rhythm is irregular, it is preferable to count for a minute and not multiply.

It is advisable to repeat the measurement for several days in a row, and then calculate the average of the results obtained.

The heart rate can also be measured at the carotid artery, placing the index finger and middle finger on the neck to the side of the trachea, and pressing lightly, until you perceive the beats, and then count the pulse in a minute.

At the doctor, the beats can also be counted by listening to the heart by means of a stethoscope placed on the chest, a measurement method that is more accurate than the previous ones or, better yet, through the electrocardiogram (ECG), typically prescribed for any form of problem related to cardiology.

Finally, for the measurement, you can also use a heart rate monitor, an electronic device that can detect the heartbeat and therefore determine the heart rate in real time, widely used by runners and athletes in general. It is usually composed of two parts: an electrode transmitter, consisting of a band to be put on the chest (the correct position is just below the nipples in men, under the breast in women), which sends the electrical signals of the heartbeat to a receiver, which, instead, is placed on the wrist. However, there are also heart rate monitors without a band, as well as models that combine the measurement of the heartbeat frequency with other parameters (calorie counting, steps, sleep monitoring, etc.).

Finally, there are also various technological tools for measuring the number of beats per minute. They range from the watch equipped with a special sensor (now integrated into many smartwatches, easily connected to your phone), to medical devices, which can also be used in the home, with more accurate sensors that allow you to make measurements more correctly and with greater reliability in detection.

How to interpret values

From the results obtained with the measurement of one’s resting heart rate, it is possible to understand if it is physiological, or if the heart beats at a speed that is too low (bradycardia) or too high (tachycardia).

The reference values for resting heart rate are:

• less than 60 beats (per minute): bradycardia
• between 60 and 90-100 beats per minute: normal
• over 100 beats per minute: tachycardia.

In general, it is good to have a resting heart rate close to the lower limit.

Most frequent abnormalities and treatments: bradycardia

Bradycardia can also occur physiologically, as in athletes and sometimes in the elderly. In these cases the resting heart rate can be less than 50 beats per minute, without however causing discomfort, nor requiring any specific therapy (unless, of course, it is due to some pathology).

Severe and rapid-onset bradycardia may require emergency treatment, such as a heart attack; In chronic forms or in all those conditions at risk of severe bradycardia, the implantation of a pacemaker may be indicated.

Symptoms and complications of bradycardia

Symptoms of bradycardia include:

• dizziness;
• misses;
• a deep sense of fatigue;
• feeling of “lack of air” with difficulty breathing.

Bradycardia is dangerous when it reaches extremely low frequencies, below 35 beats per minute. The choice of treatment depends on the cause and symptoms: they range from very simple therapeutic procedures, perhaps aimed at restoring a correct lifestyle in the patient, to appropriate breathing techniques, targeted exercises and special physical activity, up to the intake of specific drugs for the recovery of a more regular and moderate cardiac function.

Most frequent abnormalities and treatments: tachycardia

In adults, tachycardia is defined as the increase in the frequency of heartbeats above 90-100 beats per minute.

It can be due to physiological events (e.g. pregnancy, gastrointestinal disorders, physical exertion, stress) or excessive consumption of coffee, alcohol or drugs. Caffeine, theine, alcohol and this type of substance, in fact, can cause alterations in the heart rate at rest or during physical activity. The same applies to pathological conditions such as anxiety or panic.

More often, however, tachycardia is the indicator of other diseases, such as atherosclerosis or coronary insufficiency. Some forms of tachycardia do not require any treatment, while in other cases it is necessary to intervene with medication.

Symptoms and complications of tachycardia

Tachycardia can compromise the normal blood supply to the various tissues with suffering of the less supplied districts. The most common symptoms are:

• palpitations (annoying perception of heartbeat);
• faint;
• chest pain;
• dizziness.

In some people it is, on the contrary, completely asymptomatic. Excessive resting heart rate can increase the risk of suffering a stroke or cardiac arrest.

When to consult your doctor

In all cases in which there is the perception of an altered heart rate (apart from the physiological increase due to physical effort or intense stress) it is good to contact your doctor to identify the causes, and start the most suitable treatments.

Only the specialist, in fact, will be able to carry out a more in-depth evaluation and accurate monitoring of the actual heart rate, arrive at the diagnosis of a possible disorder and propose the most appropriate treatment.

Heart rate and sports

Knowing your heart rate, both resting and maximum, is also particularly useful for athletes of all levels, especially for those who dedicate themselves to an endurance sport, that is, an aerobic activity that requires a prolonged effort over time (such as cycling, swimming, some types of running such as middle-distance, trail running, etc.).

The measurement of physical training, in fact, is in direct relation to the heart rate: for sports practice to be healthy, it is important that during the movement the normal heart rate does not reach too high levels and, at the same time, is not too low, otherwise the training would be ineffective and do not allow you to improve and / or maintain your physical shape.

In addition to knowing your resting heart rate, it is good to calculate the maximum one as well.

There are several formulas for calculating the theoretical maximum heart rate.

• Cooper’s formula: 220 – age (in years)
• Astrand’s formula: 220 – age (in years) for men; 226 – age (in years), for women.

A more accurate measurement can be obtained by undergoing an electrocardiogram under stress: an examination that measures the frequency of heartbeats while the subject pedals at increasing effort on a specific bicycle (cycle ergometer) or is invited to run on a special treadmill.

By knowing your resting and maximum heart rate, you can calculate your reserve heart rate (which comes from the difference between your maximum and resting heart rate) and then plan your workout intensity. That is, you can calculate the ideal heart rate (or target heart rate) that you should maintain during sports and fitness.

To calculate it, Karvonen’s formula is used, which multiplies the reserve frequency by the percentage of work intensity you intend to do (the correct intensity can vary from 60% to 90% compared to the maximum frequency, for example 60-70% is recommended for beginners). To the result obtained is then added the frequency at rest.

Finally, in sports, it can be useful, for the purposes of training planning, to also know the anaerobic threshold, that is, the heart rate value beyond which more lactic acid is produced than what can be disposed of. In addition, the level of oxygen in the blood decreases, breathing becomes faster and performance decreases.

The value of this threshold, which the doctor measures accurately, with the dosage of lactic acid under progressive stress, varies according to the degree of training (in untrained subjects it is around 65-70% of the maximum heart rate, in athletes around 85%-90%). Athletes who intend to raise it, to improve, thus, their efficiency, must generally train at a heart rate close to that of the anaerobic threshold.