Criterion-Validity of Commercially Available Physical Activity Tracker to Estimate Step Count, Covered Distance and Energy Expenditure during Sports Conditions

Abstract

Background: In the past years, there was an increasing development of physical activity tracker (Wearables). For recreational people, testing of these devices under walking or light jogging conditions might be sufficient. For (elite) athletes, however, scientific trustworthiness needs to be given for a broad spectrum of velocities or even fast changes in velocities reflecting the demands of the sport. Therefore, the aim was to evaluate the validity of eleven Wearables for monitoring step count, covered distance and energy expenditure (EE) under laboratory conditions with different constant and varying velocities.Methods: Twenty healthy sport students (10 men, 10 women) performed a running protocol consisting of four 5 min stages of different constant velocities (4.3; 7.2; 10.1; 13.0 km·h−1), a 5 min period of intermittent velocity, and a 2.4 km outdoor run (10.1 km·h−1) while wearing eleven different Wearables (Bodymedia Sensewear, Beurer AS 80, Polar Loop, Garmin Vivofit, Garmin Vivosmart, Garmin Vivoactive, Garmin Forerunner 920XT, Fitbit Charge, Fitbit Charge HR, Xaomi MiBand, Withings Pulse Ox). Step count, covered distance, and EE were evaluated by comparing each Wearable with a criterion method (Optogait system and manual counting for step count, treadmill for covered distance and indirect calorimetry for EE).Results: All Wearables, except Bodymedia Sensewear, Polar Loop, and Beurer AS80, revealed good validity (small MAPE, good ICC) for all constant and varying velocities for monitoring step count. For covered distance, all Wearables showed a very low ICC (<0.1) and high MAPE (up to 50%), revealing no good validity. The measurement of EE was acceptable for the Garmin, Fitbit and Withings Wearables (small to moderate MAPE), while Bodymedia Sensewear, Polar Loop, and Beurer AS80 showed a high MAPE up to 56% for all test conditions.Conclusion: In our study, most Wearables provide an acceptable level of validity for step counts at different constant and intermittent running velocities reflecting sports conditions. However, the covered distance, as well as the EE could not be assessed validly with the investigated Wearables. Consequently, covered distance and EE should not be monitored with the presented Wearables, in sport specific conditions.

The Accuracy of Smart Devices for Measuring Physical Activity in Daily Life: Validation Study (Preprint)

“…The ActiGraph was therefore by approximation the best available golden standard. Third, the sample size was small, but nevertheless comparable to previous validation studies [16][17][18]31,35,41]. Fourth, the development of new wearables that appear on the market is going fast.…”

The use of fitness trackers in the training process for increasing physical and functional abilities in athletes

“…However, the current study proved that only continuous monitoring of the athlete's body can have a positive effect on the athlete's performance. Users are accustomed to customizing technology and software in accordance with their preferences and needs [20]. Therefore, the more continuous settings we can enable, the more users will be satisfied.…”

“…The organization of the experimental work was focused on targeted stimulation of students of various ages to independent physical education activities through individualization and differentiation of the use of mobile devices. The research was conducted by means of providing mobile technologies to each athlete of the experimental group stimulating them for physical self-improvement using smartphones [20]. When introducing mobile content in the training process, it was especially important that the participants would use mobile technologies only on a rational and methodically correct bassis [21].…”

Evaluation of mobile applications for fitness training and physical activity in healthy low-trained people - A modular interdisciplinary framework

“…Whereas differences between two devices of the same product (FitBit Flex) were low (range: 0 to 7%), differences between different products (FitBit Charge HR versus Garmin vivoactive; FitBit Flex versus Apple Watch) were high (range: 0 to 40%). Wahl et al (2017) tested the criterion validity of 11 different wearables (Bodymedia Sensewear, Beurer AS 80, Polar Loop, Garmin Vivofit, Garmin Vivosmart, Garmin Vivoactive, Garmin Forerunner 920XT, Fitbit Charge, Fitbit Charge HR, Xaomi MiBand, Withings Pulse Ox) in a sample of 20 healthy students. The participants performed a protocol including various running exercises (i.e., staged, intermittent, and outdoor runs).…”

“…In current reviews, two aspects are criticized, i.e., lack of user or consumer integration in the development process and lack of adequate validating research (e.g., Düking et al, 2018;Peake, Kerr, & Sullivan, 2018, Warraich, 2016. Halson et al (2016) enumerate numerous issues of mobile ICT regarding SPA and FT, ranging from technical issues like sensor placement and accuracy (see also Wahl et al, 2017) to ethical considerations. Furthermore, motivational and informational challenges have to be met (Schmidt et al, 2015).…”