What is PAI in smartwatches and is it worth focusing on this indicator

What is PAI

PAI (Personal Activity Intelligence) is a physical activity index that measures whether you are moving enough to stay healthy and prolong your life.

The calculation algorithm was developedPersonal Activity Intelligence (PAI) / Norwegian University of Science and Technology at the Norwegian University of Science and Technology and implemented first in the fitness tracker Mio Slice, and then to the Amazfit model line and some other bracelets and smart watches with constant tracking pulse.

Unlike the usual prescriptions like 10 thousand steps per day or 150 minutes of cardio activity per week, PAI allows you to determine the rate of movement more individually - based on the heart rate (HR) of a particular person, his physical form and others options.

How PAI is calculated

PAI is calculated based on heart rate and displayed as 7 days total. The specific calculation algorithm is kept secret, but the principle of its operation is simple: the more often the heart beats, the more PAI points you can earn.

Thus, the rate at which PAI is added is primarily dependent on exercise intensity. At the same time, it does not matter at all what exactly you are doing - walk, running, lift the barbell, or dash around the house with a rag in your hands.

The ideal PAI value is 100 pips.

At the same time, it is impossible to earn more than 75 points in one day, even if you run a marathon. This is done on purpose to get people to move at least twice a week.

Otherwise, the activity index provides complete freedom. You can exercise for 8-10 minutes every day, or arrange two killer 20-minute intervals, and the rest of the time you move only from the refrigerator to the sofa - and still get 100 PAI.

Since heart rate is directly related to weight and training level, the indicators will differ from person to person.

For example, a professional runner's heart rate during a light jog can rise in about the same way as an inactive person with being overweight with simple walking. And PAI will be counted to them the same.

Moreover, since the heart rate decreases during activity with increasing fitness, over time you will need to move more to get the same PAI per week.

What affects the amount of activity per week

Scientists have checkedB. M.Nes, U. Wisløff. Personalized Activity Intelligence (PAI) for Prevention of Cardiovascular Disease and Promotion of Physical Activity / The American Journal of Medicine PAI algorithm using health information of several thousand Norwegiansliving in the county of Nur-Trøndelag. The data were collected several times: first in 1984-1986, and then from 2006 to 2008.

Using this information, the scientists determined the degree of people's habit of physical activity - how much they moved, how often and how intensively they did it - and calculated the approximate PAI for each week.

It turned out that men and women with PAI 100, compared with people with zero activity, by 17% and 23% less risk of dying from cardiovascular diseases (CVD) and 13-17% less risk of dying from any reasons.

Scientists estimate that people with PAI 100 live on average 4.7 years longer than inactive people with an index of 0.

About the same was found in the analysisJ. Naumanabc, X. Suid, C. J.Lavie. Personal activity intelligence and mortality - Data from the Aerobics Center Longitudinal Study / Progress in Cardiovascular Diseases data of 56 thousand Americans for 14 years. Here PAI 100 extended the life span of people by an average of 4.2 years.

Moreover, the likelihood of dying from CVD or other reasons decreased regardless of age, smoking history, hypertension, excess weight, and existing problems. 1. Personal Activity Intelligence and Mortality in Patients with Cardiovascular Disease: The HUNT Study
2. A. L. Hannan, W. Hing, J. S. Coombes. Effect of personal activity intelligence (PAI) monitoring in the maintenance phase of cardiac rehabilitation: a mixed methods evaluation / BMC Sports Science, Medicine and Rehabilitation volume
3. N. Ziskoa, K. N. Skjervea, A. R.Tari. Personal Activity Intelligence (PAI), Sedentary Behavior and Cardiovascular Risk Factor Clustering - the HUNT Study / Progress in Cardiovascular Diseases with heart and sedentary lifestyle.

Interestingly, values ​​above a hundred did not provide additional benefits to mitigate risks, although they did not cause harm. Thus, PAI 100 reflects the ideal amount of movement for health.

Should I focus on this PAI indicator?

The methodology for calculating PAI was not tested in long-term randomized studies, but through data analysis, collected at certain periods in the past, and therefore the results may well differ from reality.

And even if the algorithm is actually perfect, the accuracy can be degraded by gadgets. Fitness trackers track your heart rate well at rest and while moving may underestimate the indicator by 6-11%.

Despite this, PAI seems to be a good tool for assessing the level of physical activity. Even if scientists are mistaken or exaggerated the accuracy of the new metric, additional training will not harm you, and the desire to see the cherished hundred will be a good source of motivation.

Where to track the amount of activity

This function is availableWhich devices are supported? / PAI Health Support in fitness trackers and watches Fitbit and Amazfit. You can also track your health items using the PAI Health app using your Apple Watch and Polar devices in training mode.

New technology appeared in Xiaomi Mi bracelets Band 5 and 6, but they are not synchronized with PAI Health yet. The data can be viewed on the devices themselves or in the Mi Fit app.

In the future, PAI Health plansWill PAI work with my device? / PAI Health add the ability to download data from Google Fit, Samsung and Xiaomi Mi Band, but so far there are no such options in the application.

How long does it take to get 100 PAI

In researchB. M. Nes, U. Wisløff. Personalized Activity Intelligence (PAI) for Prevention of Cardiovascular Disease and Promotion of Physical Activity / The American Journal of Medicine noted that to reach 100 points, it is enough to move for 40 minutes at a heart rate of about 160–170 beats per minute or 60 minutes at 150–160 beats per minute.

Moreover, the less intense the activity, the longer it will take to work to gain the required amount of PAI.

For example, 2.5 hours of light exercise on a heart rate of about 130 beats per minute will provide only 38 points, while one interval training lasting 20 minutes on a heart rate of about 170 beats will help you gain 50 or more PAI.

Since the indicator is calculated per week, no one bothers you to combine workouts of different intensities in any way.

Moreover, it is not necessary to immediately strive for 100 points, resorting to exhausting loads. For those who are out of the habit of physical activity, even 50 PAI will be a real achievement and a plus for health and longevity.