How Does a Fitness Tracker Work?

It's always good to be curious about how things work because then you begin to properly understand the significance of their functions. A fitness tracker sits perfectly on your wrist, counting the number of steps you make, measuring calorie expenditure and monitoring the quality of your sleep. Yet just how exactly does this gadget collect information and relay it to your smartphone?

To explain it simply, fitness tracking devices measure motion. Most of the current trackers have accelerometers that track movements in all directions. Some also measure orientation using a gyroscope. The data gathered is afterwards converted into activity and steps and then sleep quality and calories. Some assumptions are made on the way to arriving at these information. 

The altimeter, as the name suggests, is a feature used for measuring altitude. It is very important in measuring the heights of mountains when you are working out at high altitudes and the number of flights of stairs taken in a day. All these information is gathered and compiled to create a general reading. The accuracy of the data will increase with the number of sensors that your tracker has. 

The sensors of the tracking device determine acceleration, duration, frequency, intensity and movement patterns. All this data collected together improves the accuracy of your tracker reading. The sensors will collect information whether you are enjoying evening walks or just dancing to your favorite music.

Other trackers have temperature sensors that check the body temperature alongside bio-impedance sensors that measure the resistance of the skin to small electric currents. Some fitness trackers make use of optical or light sensors to measure pulse by shining light on the skin. The light illuminates capillaries as the sensors take measurements of how fast your blood is flowing and subsequently the rate of your heartbeat. These sensors come in handy when you are working out and want to monitor your heartbeat. Bio-impedance sensors are however more effective in gauging your general health.

When monitoring the quality of your sleep, the trackers use a process known as actigraphy to translate wrist movements into patterns of sleep. It will ideally measure how much you toss and turn in your sleep. To measure the amount of calories burned, a tracker will add heart rate data and amount of perspiration into the algorithm plus the number of steps taken. 

Fitness trackers use algorithms that differ slightly to convert raw data into real statistics. Different trackers have different thresholds for collecting information and that's why some trackers will ignore a small body movement like stretching while others will record it. This has an effect on the accuracy of the final data presented. As you purchase your fitness tracking device, you'll be asked about your age, weight, height and gender in order to find one that greatly suits you.

The final link in this chain is the smartphone app. Once the data goes through numerous algorithms and then refined appropriately, it is presented in a format that is user-friendly. A lot of fitness tracking applications also come with the capability of adding data manually.