Calorie tracking has become an essential feature in various fitness devices, and Garmin is no exception. With its range of wearable fitness trackers and smartwatches, Garmin offers users the ability to monitor their calorie expenditure throughout their daily activities and workouts. But how does Garmin calculate these calories? In this article, we will explore the algorithms and data utilized by Garmin devices to provide accurate calorie estimates.

1. Basal Metabolic Rate (BMR)

Before diving into workout-specific calculations, it’s essential to understand that our bodies burn calories even while at rest. This baseline energy expenditure is called Basal Metabolic Rate (BMR). Garmin calculates a user’s BMR based on personal information such as age, gender, weight, and height. The Harris-Benedict equation and Mifflin-St Jeor equation are two commonly used formulas to estimate BMR.

2. Activity Level

For a more accurate calorie estimate, Garmin uses data gathered from its built-in sensors to assess the user’s overall activity level throughout the day. This includes activities such as walking, running or doing household chores. By multiplying the BMR with an activity factor (ranging from sedentary to extremely active), the tracker estimates Total Daily Energy Expenditure (TDEE).

3. Heart Rate Data

One of the critical features in many Garmin devices is heart rate monitoring. Using heart rate data, the device can calculate calories burned during exercise more accurately. The algorithm incorporates factors like heart rate reserve (HRR) – which is the difference between resting heart rate and maximum heart rate – and duration of exercise into the calculation.

4. MET Values

Garmin also utilizes Metabolic Equivalent of Task (MET) values in estimating calorie burn for various activities. MET is a standardized measure representing the energy cost of a specific activity compared to being at rest (1 MET = resting energy expenditure). Activities with higher MET values, such as running or swimming, burn more calories than those with lower MET values, like walking or yoga.

5. GPS Data and Speed

For outdoor activities like cycling and running, Garmin devices with built-in GPS calculate calorie burn based on the user’s speed, distance covered, and elevation changes. The data generated by the GPS allows the device to take into account factors like wind resistance and surface gradient when determining the energy expenditure of the activity.

6. Firstbeat Algorithm

Some Garmin devices use Firstbeat’s proprietary algorithms, which incorporate heart rate variability (HRV) data into calorie calculations. HRV is an effective measure of stress and fatigue within the body, allowing for a more accurate portrayal of energy expenditure during exercise.

In conclusion, Garmin calculates calories burned through a combination of personal information, activity data, heart rate metrics, MET values, GPS details, and advanced algorithms. By integrating multiple sources of information, Garmin aims to provide users with an accurate assessment of their daily calorie expenditure, helping them make informed decisions regarding their fitness goals and nutritional needs.