▎ WuXi AppTec content team editor
Changes in heart rate before and after exercise are inextricably linked to our heart health. Let's talk to you today.
The relationship between exercise intensity and heart rate
When it comes to exercise intensity, these words are often mentioned – low intensity (small intensity), medium intensity and high intensity (high intensity) exercise.
How do you define its intensity?
We know that the more intense the exercise, the more pronounced the heart's response to exercise stimuli and the faster the heart rate. Therefore, it is mainly divided according to heart rate.
In 2017, the General Administration of Sport of China explained this issue in its interpretation of the National Fitness Guidelines, as follows:
Small-intensity exercise: the stimulation effect on the body is small, and the measured heart rate during exercise generally does not exceed 100 times/ min, such as walking. ：
Moderate-intensity exercise: moderate stimulation of the body, the heart rate during exercise is generally 100 to 140 beats / min, such as walking, jogging, cycling, tai chi, tennis doubles, etc.
High-intensity exercise: The stimulation intensity of the body is large, which can further improve the fitness effect. The sports center rate exceeds 140 beats per minute, such as running, fast cycling, fast-paced aerobics and fast climbing, stair climbing, tennis singles, etc.
Image credit: 123RF
Exercise Selection Recommendations:
People with good exercise habits and good physique can carry out high-intensity and medium-intensity exercise;
People with certain exercise habits and good physique can use moderate-intensity exercise;
People who participate in physical fitness activities in the early stages or have a weak constitution can exercise moderate or small intensity exercise.
That is to say, for most ordinary people, that is, people in categories 2 and 3 (general or weak physical fitness), it is recommended to try to focus on moderate intensity and below exercise, which does not have a heart rate of more than 140 beats per minute.
Of course, in the specific fitness activities, you can also scientifically adjust the exercise intensity according to your own situation, so that you can gradually adapt to and challenge higher goals.
How to assess whether your own qualities are suitable for high-intensity sports?
The first thing to do is calculate what your own theoretical maximum heart rate is during exercise.
How is the maximum heart rate calculated during exercise?
The maximum heart rate is the fastest heartbeat rate that can be achieved during human movement.
The most accurate measurement method is direct assay, but it requires incremental load motion testing in a specialized testing institute, as well as specialized motion testing instruments and equipment.
Another method is simpler, estimated using a formula, as studies have found that the maximum heart rate in normal people is mainly related to age:
Max heart rate (times/min) = 220 - age (years)
Therefore, for people of different ages, we can divide the exercise intensity that suits us according to the situation:
Heart rate at or above the maximum heart rate: equivalent to high-intensity exercise;
Heart rate is controlled in the range of 60% to 85% of the maximum heart rate: equivalent to moderate-intensity exercise;
Heart rate is controlled in the range of 50% to 60% of the maximum heart rate: equivalent to small-intensity exercise.
For example, Xiaoming is 30 years old this year, and his maximum heart rate is theoretically 190 beats per minute. When the measured heart rate exceeds 161.5 beats per minute, it is high-intensity exercise for him;
And Xiaoming's father is 60 years old this year, his maximum heart rate is only 160 beats / min, as long as the heart rate exceeds 136 beats / min, it is high-intensity exercise.
Nowadays, many people wear sports bracelets and armbands when exercising, and it is very convenient to measure the heart rate. And the study found that the accuracy of these devices is also relatively reliable.
Image credit: 123RF
If there are no conditions, it is also possible to simply estimate the heart rate situation through breathing and subjective physical feelings.
Image source: China General Administration of Sport[1]
(Note: "Shortness of breath" means that only short sentences can be spoken during exercise, and long sentences cannot be fully expressed; "shortness of breath" refers to difficulty breathing and inability to converse in language during exercise.) ）
To add to this, unlike aerobic exercise, the division of strength exercises is not based on heart rate, but on the weight of the load.
Large intensity is equivalent to 1~10RM, medium intensity is equivalent to 11~20RM, and small intensity is equivalent to 20RM or above (there is also the difference in the frequency of the number of actions, which will not be expanded here).
Image credit: 123RF
Where is the warning line for heart rate during exercise?
Back to the previous topic, why is 85% a "cordon"?
In fact, this is also one of the auxiliary diagnostic indicators for local myocardial ischemia (coronary heart disease) in medicine.
Some people may already have abnormal cardiovascular function, but in the case of resting (resting), because coronary blood flow can remain normal, it does not show cardiac physiological stress response, and there are no symptoms of myocardial ischemia.
Even, their ECG may be completely normal.
How do you expose the problem? Exercise stress testing (also known as flat exercise test, electrocardiogram exercise test, exercise stress test) is used to induce and find areas of ischemia that are potential and at risk of infarction.
In layman's terms, it is to jog on a special treadmill in the hospital and monitor your exercise electrocardiogram at the same time.
When do you stop?
The general international consensus is that when the heart rate reaches 85% of your expected maximum heart rate of your age, or until symptoms appear, whichever occurs first will prevail.
During this process, some ECG abnormalities may be detected.
However, some studies have found that after more than 85%, more abnormalities may be found, so this "warning line" may also need to be combined with other indicators.
In 2019, a study published in the European Journal of Preventive Cardiology asked 460 healthy people (ages 24 to 62) to undergo exercise stress tests and found that most people in actual exercise had a peak heart rate that exceeded 85% of their expected maximum heart rate when they exercised to exhaustion.
When it is exceeded, the body's fatigue feeling score (RPE score) has not yet reached the "most tired" level.
Image credit: 123RF
The study also found that 35% of cardiovascular abnormalities were exposed after "85%", including:
Complex ventricular arrhythmias, ECG ST-T segment changes, cardiovascular abnormalities (including aortic regurgitation, mitral regurgitation, left ventricular hypertrophy, hypertensive cardiomyopathy, mitral valve prolapse).
Then push back, when we exercise on our own, it is likely that we will unconsciously exceed 85% of the maximum heart rate and do not feel particularly tired.
Once exceeded, there may be some cardiovascular problems that are not usually found to be exposed, and dangerous conditions such as myocardial infarction are more likely to occur.
How to gradually increase the intensity of exercise?
Finally, it is recommended that you choose sports according to your actual situation.
According to China's "National Fitness Guide", for people who usually lack exercise, it is necessary to take it step by step, starting from low- to medium-intensity exercise and then transitioning to high intensity.
1. Initial adaptive workout (just started with exercise): 8 weeks
Mode: moderate-intensity aerobic exercise, ball sports, traditional Chinese exercise methods, flexibility exercises.
Intensity: Gradually increases from 55% maximum heart rate to 60%.
Duration: Gradually increase from 10 to 20 minutes each time to 30 to 40 minutes.
Frequency: Gradually increased from 3 days/week to 5 days/week.
2. Mid-stage enhancement phase (improvement in physical ability): 8 weeks
How: Maintain the initial fitness style; increase strength exercises appropriately.
Intensity: The maximum heart rate of aerobic exercise gradually increases from 60% to 65% to 70% to 80%; anaerobic exercise can be arranged once a week, and the strength exercise is repeated 6 to 8 times with a load of more than 20RM.
Duration: 30 to 50 minutes each time; 10 to 15 minutes each time if there is anaerobic exercise; 1 to 2 strength exercises per week, 6 to 8 muscle strength exercises each time, repeat 1 to 2 groups each time; 5 to 10 minutes of traction exercises.
Frequency: 3 to 5 days/week.
3. Long-term maintenance phase (body function has reached a high level)
How: Maintain a mid-term fitness style.
Intensity: Moderate-intensity exercise, equivalent to 60% to 80% of the maximum heart rate, high-intensity exercise can reach more than 80% of the maximum heart rate; strength exercises, can use 10 to 20RM load, repeat 10 to 15 times; various stretching exercises.
Duration: 30 to 60 minutes of moderate-intensity exercise, or 15-25 minutes of high-intensity anaerobic exercise, or alternating exercise mode of moderate and high-intensity exercise; 8 to 10 kinds of muscle strength exercises, repeat 2 to 3 sets each time, and perform 5-10 minutes of stretching exercises each time.
Frequency: 5 to 7 days / week, high-intensity exercise does not exceed 3 times a week.
During exercise, be sure to pay more attention to your heart rate. Again, if there is any discomfort, don't brace yourself, stop in time to rest.