title: Accuracy and Adoption of Wearable Technology Used by Active Citizens: A Marathon Event Field Study.
abstract: BACKGROUND
  Today, runners use wearable technology such as global positioning system (GPS)-enabled sport watches to track and optimize their training activities, for example, when participating in a road race event. For this purpose, an increasing amount of low-priced, consumer-oriented wearable devices are available. However, the variety of such devices is overwhelming. It is unclear which devices are used by active, healthy citizens and whether they can provide accurate tracking results in a diverse study population. No published literature has yet assessed the dissemination of wearable technology in such a cohort and related influencing factors.
  
  
  OBJECTIVE
  The aim of this study was 2-fold: (1) to determine the adoption of wearable technology by runners, especially "smart" devices and (2) to investigate on the accuracy of tracked distances as recorded by such devices.
  
  
  METHODS
  A pre-race survey was applied to assess which wearable technology was predominantly used by runners of different age, sex, and fitness level. A post-race survey was conducted to determine the accuracy of the devices that tracked the running course. Logistic regression analysis was used to investigate whether age, sex, fitness level, or track distance were influencing factors. Recorded distances of different device categories were tested with a 2-sample t test against each other.
  
  
  RESULTS
  A total of 898 pre-race and 262 post-race surveys were completed. Most of the participants (approximately 75%) used wearable technology for training optimization and distance recording. Females (P=.02) and runners in higher age groups (50-59 years: P=.03; 60-69 years: P<.001; 70-79 year: P=.004) were less likely to use wearables. The mean of the track distances recorded by mobile phones with combined app (mean absolute error, MAE=0.35 km) and GPS-enabled sport watches (MAE=0.12 km) was significantly different (P=.002) for the half-marathon event.
  
  
  CONCLUSIONS
  A great variety of vendors (n=36) and devices (n=156) were identified. Under real-world conditions, GPS-enabled devices, especially sport watches and mobile phones, were found to be accurate in terms of recorded course distances.
authors.affiliation: GECKO Institute for Medicine, Informatics & Economics, Heilbronn University, Heilbronn, Germany.|Consumer Health Informatics SIG, German Association for Medical Informatics, Biometry & Epidemiology (GMDS e.V.), Cologne, Germany.
authors.forename: Monika
authors.identifier: http://orcid.org/0000-0002-9925-2173
authors.initials: M
authors.lastname: Pobiruchin
authors.affiliation: Department of Medical Informatics, Heilbronn University, Heilbronn, Germany.
authors.forename: Julian
authors.identifier: http://orcid.org/0000-0002-0652-111X
authors.initials: J
authors.lastname: Suleder
authors.affiliation: Department of Medical Informatics, Heilbronn University, Heilbronn, Germany.
authors.forename: Richard
authors.identifier: http://orcid.org/0000-0003-1236-7398
authors.initials: R
authors.lastname: Zowalla
authors.affiliation: Consumer Health Informatics SIG, German Association for Medical Informatics, Biometry & Epidemiology (GMDS e.V.), Cologne, Germany.|Department of Medical Informatics, Heilbronn University, Heilbronn, Germany.
authors.forename: Martin
authors.identifier: http://orcid.org/0000-0003-3346-9633
authors.initials: M
authors.lastname: Wiesner
keywords: activity monitoring; athlete; mobile phones; physical activity; wearables