#Accurate calorie tracker portable

To date, most studies analyze accuracy over an entire activity bout in comparison to assessing heart rate accuracy in response to different levels of physical activity intensity. The need for validation is especially important as each of these represent additional technology for behavioral interventions. The Apple Watch was found to underestimate both heart rate and EE, with a tendency to underestimate calories expended by more than 100 calories. Moreover, although the Apple Watch has become very popular, it has only been used in one validation study. We can find no efforts to validate the Garmin Forerunner 225. For example, the Forerunner was used to show that, in children, decreased time spent in outdoor environments is associated with increased body weight and lower levels of MVPA. For Garmin devices, most validation studies focus on the Garmin Vivofit, although Forerunner models have been used in built environment studies. Fitbit Charge HR has been found to underestimate heart rate and EE with further examination showing the device to have the greatest error in light to moderate physical activity and least amount of error in vigorous physical activity. There have been limited validity studies regarding these more recent devices. PPG uses a light source to illuminate the tissue of the wrist and a photodetector to measure variations in light intensity associated with changes in perfusion. PPG is a simple and low-cost optical technique that detects blood volume changes in the microvascular bed of tissue.

These more recent wearable physical activity devices, which include a measure of heart rate, utilize photoplethysmography (PPG) to measure heart rate. However, it should be noted that these devices are not the only commercial devices in the market.

#Accurate calorie tracker portable

These devices were selected based on review of sales data in 3 categories of wearable devices-smart watches, basic wearable bands, and portable navigation devices. To this end, our study assesses the Apple Watch, Fitbit Charge HR, and Garmin Forerunner 225. It is important to validate current devices, especially those that are most popular. However, given the pace of technological change, these existing studies have largely been completed on devices that would be considered outdated, such as earlier Fitbit models (One, Zip, Flex, Ultra), Jawbone Up, and the Nike FuelBand.

Most research has primarily focused on the accuracy of estimates of EE. As monitors grow as an intervention tool, questions of validity become paramount and it is important to assess their accuracy for this purpose.Īccuracy is measured by evaluating the device against a research-grade criterion measure. With the increase in popularity, wearable-based behavioral change interventions are becoming more prevalent. In 2015, 232 million wearable electronic devices were sold worldwide, with a projected 18.4% increase in sales for 2016. In addition to physical activity and energy expenditure (EE), more recent wearable models are designed to measure heart rate at the wrist. Commercial physical activity tracking wearable devices have emerged as an increasingly popular method for consumers to assess their daily activity and calories expended. According to self-report data, the proportion of adults meeting the guidelines was 62.0%, but this dropped to 9.6% for accelerometry measures of activity, which illustrates the importance of objective measures of activity. The Physical Activity Guidelines for Americans suggest adults achieve 150 minutes of moderate to vigorous physical activity (MVPA) per week. The device measured higher EE at all stages ( P<.001). The device measured higher HR readings at start, baseline, light intensity, moderate intensity ( P<.001), and recovery ( P=.04). HR was not significantly different at vigorous intensity ( P=.35).

For Garmin Forerunner 225, HR MAPE was between 7.87% and 24.38%. EE was not significantly different at vigorous ( P=.70) or recovery ( P=.10). The device measured higher EE at baseline ( P=.003), light intensity ( P<.001), and moderate intensity ( P=.001). HR was not significantly different at the start ( P=.67) or during moderate intensity ( P=.34) lower HR readings were measured during baseline, vigorous intensity, and recovery ( P<.001) and higher HR during light intensity ( P<.001). For the Fitbit device, the HR MAPE was between 2.38% and 16.99%.

The device measured higher EE at all stages ( P<.01). HR was not significantly different at the start ( P=.78), during baseline ( P=.76), or vigorous intensity ( P=.84) lower HR readings were measured during light intensity ( P=.03), moderate intensity ( P=.001), and recovery ( P=.004). For the Apple Watch, HR MAPE was between 1.14% and 6.70%.