Shine estimates your total calories burned each day, which includes: (1) calories related to your physical activities like walking, running, swimming, etc; and (2) the basal metabolic rate (BMR) of energy needed just to keep your body alive.
The calories consumed by your physical activities are based on their duration and intensity, which are measured by Shine’s three-dimensional accelerometry system. BMR is estimated from your height, weight, age, and sex. Since BMR usually accounts for the vast majority (at least 2/3) of calories we consume daily, one can typically expect the majority of calories on the app to be a reflection of BMR, with a more modest contribution from physical activity.
One technical point is that strictly speaking, BMR only includes the calories needed to maintain our vital organs (e.g. brain, heart, lungs, etc.) at rest but does not include the energetic cost of digesting the food we eat (that’s right, it takes calories to consume calories!). This adds about another 10% to the combined energetic cost of rest (BMR) and activity. Shine takes this into account as well in estimating total calories.
Here’s an example: if your BMR is 80 calories per hour (about 2000 cals/day), then syncing your Shine at noon would show about 1000 calories even if you haven’t done any physical activity. If you did walk for 30 minutes in the morning, you might burn an extra 100 calories; a 30 minute jog might earn you a couple hundred calories depending on your pace etc. We wanted to show you your caloric expenditure, but we recognize that activity-related calories become easily dwarfed by the BMR. And studies suggest that independent of calories or other factors, physical activity itself is among the most important contributors to an individual’s well being — that’s why Shine’s primary display is activity points, a reflection of physical activity, pure and simple. No activity, no points; lots of activity, lots of points. It’s that simple.
We are continuously refining our algorithms and calculations based on increasing data and research. Stay tuned for upcoming infographics with more information on caloric expenditure, basal metabolic rate, the thermal effect of food, and the benefits of an active lifestyle.