Personal Activity Intelligence (PAI): A new standard in activity tracking for obtaining a healthy cardiorespiratory fitness level and low cardiovascular risk

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Abstract

Despite all the evidence of health benefits related to physical activity (PA) and cardiorespiratory fitness (CRF), low levels of PA have reached pandemic proportions, and inactivity is the fourth leading cause of death worldwide. Lack of time, and inability to self-manage are often cited as main barriers to getting adequate PA. Recently, a new personalized metric for PA tracking named Personal Activity Intelligence (PAI) was developed with the aim to make it easier to quantify how much PA per week is needed to reduce the risk of premature mortality from non-communicable diseases. PAI can be integrated in self-assessment heart rate devices and defines a weekly beneficial heart rate pattern during PA by considering the individual's sex, age, and resting and maximal heart rates. Among individuals ranging from the general population to subgroups of patients with cardiovascular disease (CVD), a PAI score ≥100 per week at baseline, an increase in PAI score, and a sustained high PAI score over time were found to delay premature death from CVD and all causes, regardless of whether or not the current PA recommendations were met. Importantly, a PAI score ≥100 at baseline, maintaining ≥100 PAIs and an increasing PAI score over time was associated with multiple years of life gained. Moreover, obtaining a weekly PAI ≥100 attenuated the deleterious association between CVD risk factor clustering and prolonged sitting time. PAI and objectively measured CRF (as indicated by VO2peak) were positively associated in a graded fashion, and individuals with a PAI score between 100 and 150 had expected age and sex specific average VO2peak values. A PAI score ≥100 was associated with higher VO2peak in both men (4.1 mL·kg−1·min−1; 95% CI, 3.5 to 4.6) and women (2.9 mL·kg−1·min−1; 95% CI, 2.4 to 3.3), compared to the reference group of <100 PAI. The combined analysis of PAI, PA and VO2peak demonstrated that a PAI score ≥100 was associated with high VO2peak values regardless of meeting or not meeting the current PA recommendations. Collectively, these findings suggest that PAI has the potential to be a useful tool to motivate people to become and stay physically active by quantifying the amount of PA needed to produce significant health benefits.

Section snippets

PAI and cardiovascular disease (CVD) risk

Among individuals ranging from the general population to subgroups of patients with CVD, a PAI score ≥100 per week at baseline, an increase in PAI score, and a sustained high PAI score over time were found to delay premature death from CVD and all causes, regardless of whether or not the current PA recommendations were met.19,24,25

In a study on 19,269 men, and 20,029 women free from known CVD at baseline and followed up for 26.2 (SD 5.9) years,19 a PAI score of ≥100/week was associated with a

Linking PAI and CRF

The characteristics of the study participants used to establish the association between PAI and CRF are presented in Table 1 (for methods, see Online Supplement). The mean VO2peak was 36.0 ± 7.7 mL·kg−1·min−1 and 44.4 mL·kg−1·min−1 for women and men, respectively. In total, 55.3% achieved a ≥100 PAI score, and 7.6% of the participants (10.5% of men and 4.9% of women) were classified as inactive (0 PAI).

There was a graded positive association between PAI and VO2peak in both men and women as

Conclusions

PAI is an easily understandable and scientifically proven PA metric. If applied more broadly, it has the potential to be a useful tool to motivate people to become and stay physically active. The impact of higher PAI in reducing the risk of premature CVD and all-cause mortality, and attenuating the deleterious effects of prolonged sedentary time have been well documented in recent years. Furthermore, we observed a graded positive association between PAI and VO2peak in both men and women. These

Acknowledgments

The Nord-Trøndelag Health Study (the HUNT Study) is a collaboration between the HUNT Research Centre (Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology NTNU), the Nord-Trøndelag County Council, Central Norway Regional Health Authority and the Norwegian Institute of Public Health. We are appreciative of the participants from the HUNT study, and the management of the study for using these data.

Statement of conflict of interest

Professor Wisløff is the inventor of PAI, and scientific advisor of a company (PAI Health Inc.) that holds the IP rights for PAI that develops applications that utilize data from diverse heart rate monitors to display PAI for users. Due to the potential conflict of interest, we are thankful to Professor Sigurd Steinshamn at Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, NTNU who monitored adherence to design, and statistical analysis in the current study.

References (39)

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