Physical activity is one of the key strategies used by public health agencies to combat the growing burden of obesity and non-communicable diseases. Adults around the world are recommended to engage in at least 150 minutes of moderate or 75 minutes of vigorous intensity activity per week, or a combination of moderate or vigorous activity that results in approximately the same total energy expenditure. However, majority of the population does not meet the physical activity recommendation. As barriers to physical activity, people mostly cite lack of time, self-motivation and confidence in the ability to be physically active. Cardiac Exercise Research Group (CERG) at Faculty of Medicine and Health Sciences at Norwegian University of Science and Technology recently developed Personal Activity Intelligence (PAI). PAI is a result of research based on the HUNT study where more than 60 000 individuals has been monitored over a period of more than 20 years. The goal is to make PAI the new world standard of activity tracking. PAI is an individual metric that makes sense of measured heart rate data, and significantly reduces the risk of lifestyle related diseases.