Personal Activity Intelligence (PAI)

Exercise enough to get 100 PAI every week, and give yourself the best possible outlook for a long and healthy life.


What is PAI?

PAI is short for Personal Activity Intelligence. You earn PAI points every time your heart rate increases: The higher heart rate, the faster you earn PAI. Our research shows that those who achieve 100 PAI or more every week over time live for an average of more than eight years longer than others.

PAI is based on the only thing that reflects the intensity of your activity: your heart rate. Everything you need to do in order to use PAI is to measure your heart rate continuously. In 2016, PAI was integrated in the Mio Slice activity tracker. Now, PAI can also be tracked with Apple Watch, Fitbit and several other devices that measure heart rate. If the score on your wrist or smart phone reads 100 or more, you are probably physically active enough. If it reads less than 100, you could reduce your own health risk by exercising more.

Why PAI and why 100?

More than five million deaths worldwide could have been prevented if people were more physically active. We believe that PAI could contribute to prevent cardiovascular disease and premature death by encouraging everyday people to be more active.

Our research shows that men and women in all age groups have far lower risk of early death and death from cardiovascular diseases if they exercise enough to obtain 100 weekly PAI. 100 PAI is optimal for smokers, obese persons, and individuals with hypertension or type 2 diabetes. Even those who achieve 50 PAI each week have considerable health benefits compared to those who are inactive.

We developed the PAI algorithm by using information from almost 5000 healthy Norwegians who had their maximum oxygen uptake tested during the HUNT3 Fitness Study. After that, we estimated PAI points for almost 40 000 healthy participants from the first HUNT study back in the 1980s. All of them had reported how much and how intense they exercised. Finally, we checked the health status of these 40 000 Norwegians almost 30 years later. The results showed that 100 PAI is optimal to reduce the risk of disease.

Read the full research article:
Personalized Activity Intelligence (PAI) for Prevention of Cardiovascular Disease and Promotion of Physical Activity

Even if you exercise too little to achieve 100 PAI, it's not too late to start now. We looked at how increasing the PAI score over time affected mortality, and found that those who increased from less than 100 PAI a week in the first survey up to at least 100 PAI a week in the next survey eleven years later had lower risk of dying early than those who stayed below 100 PAI over time. The lowest risk was found in those who were physically active enough to reach 100 PAI or more at both the HUNT1 and HUNT2 surveys.

Read the full research article:
Temporal Changes in a Novel Metric of Physical Activity Tracking (Personal Activity Intelligence) and Mortality: The HUNT Study, Norway

Improved fitness with 100 PAI

Men and women with 100 weekly PAI or more also have significantly higher cardiorespiratory fitness than those with less than 100 weekly PAI. Obtaining 100–150 weekly PAI seems to secure having the average cardiorespiratory fitness expected for your age and sex.

High cardiorespiratory fitness is closely linked to good health and increased length of life. Importantly, the magnitude of the difference in cardiorespiratory fitness between those with higher and lower PAI scores than 100 is clinically relevant, and could possibly explain the effect of 100 weekly PAI on current and future health risk.

Read the full research article:
Personal activity intelligence (PAI): A new standard in activity tracking for obtaining a healthy cardiorespiratory fitness level and low cardiovascular risk

Better than today's recommendations

PAI considers your age, your gender, your resting heart rate and your maximum heart rate. In other words, PAI is not based on the number of steps you walk or how many minutes of physical activity you perform each day. Those measurements do not consider the intensity of the activity, which could make PAI a more accurate and attractive activity standard to decide if you exercise enough.

Today's recommendations state that adults should be physically active with moderate intensity for at least 150 minutes every week, or with high intensity for at least 75 minutes. Our research, however, clearly show that even those who don't meet these activity standards have reduced risk of early death if they obtain 100 weekly PAI or more. Moreover, those who attended to the activity recommendations did not have reduced risk if they achieved less than 100 PAI every week.

100 PAI also for heart and stroke patients

Also people with cardiovascular disease should aim for 100 PAI to live longer. We estimated PAI in more than 3000 participants with previous myocardial infarction, angina or stroke from the HUNT1 Study, and followed them for up to 30 years. Those who achieved 100 PAI or more had 36 % lower risk of dying from cardiovascular causes compared to inactive patients. They also lived for an average of 5 years longer than those who earned less than 100 PAI. To achieve 100 PAI was a better predictor of future health benefits than achieving today's exercise recommendations.

Read the full research article:
Personal Activity Intelligence (PAI) and Mortality in Patients with Cardiovascular Disease, the HUNT study

In another study, we showed that persons who exercise enough to get 100 PAI each week can sit a lot without having increased cardiovascular risk. The odds of having several cardiovascular risk factors was not increased compared to those who both had 100 PAI and low levels of sedentary behaviour.

Read the full research article:
Personal Activity Intelligence (PAI), Sedentary Behavior and Cardiovascular Risk Factor CLustering – the HUNT Study

How to earn 100 PAI

It doesn't matter what type of activity you do to earn PAI – you could walk, run, cycle, row, swin or go skiing. All that matters is how high your heart rate is during the activity. You will get 100 in one hour if the intensity is 80 % of your maximum heart rate. Two and a half hours of activity of moderate intensity, however, will not give you more than approximately 45 PAI.

The better your fitness is, the more physical activity you need to achieve a 100 PAI. In other words, PAI adjusts to your progress. If you are untrained and out of shape, you could earn your 100 PAI just by going for short walks, as that will raise your heart rate. If you are in shape and well trained, you will need to do more. Getting a PAI score of 100 is the goal for everyone, and no one has to be active every single day to get there.

It is easier to reach the first 50 PAI compared to the next 50. That is because the risk reduction for lifestyle diseases is greatest when progessing from inactivity to some physically activity. This means that if you repeat a workout two days in a row, you will get less PAI the second time around. You can achieve a maximum of 75 PAI points in one day.


PAI in the media

PAI is the best example yet of how wearables can turn data about our bodies into tailored, actionable advice—and hopefully longer lives.

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Mio has once again leapfrogged the competition, this time with the release of the SLICE, an unprecedented activity tracker that analyzes a user's heart rate and, crucially, their individual response to exercise to tell them exactly how much exercise they should be doing to achieve and maintain optimal health.

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The Mio SLICE is a wrist-worn activity tracker with optical heart rate sensors that gives wearables a score—called PAI, or Personal Activity Intelligence—instead of simply telling them how many steps they've taken or estimating how many calories they've burned. 

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An all-day tracker with a fresh take on keeping you healthy.

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Infographic: PAI and your health