Low-Cost Consumer-Based Trackers to Measure Physical Activity and Sleep Duration Among Adults in Free-Living Conditions: Validation Study

Laurent Degroote   ^{1, 2, 3} , MSc ;   Gilles Hamerlinck   ¹ , BSc ;   Karolien Poels   ⁴ , PhD ;   Carol Maher   ⁵ , PhD ;   Geert Crombez   ² , PhD ;   Ilse De Bourdeaudhuij   ¹ , PhD ;   Ann Vandendriessche   ⁶ , MSc ;   Rachel G Curtis   ⁵ , PhD ;   Ann DeSmet   ^{1, 3, 4, 7} , PhD

¹ Department of Movement and Sports Sciences, Ghent University, Ghent, Belgium

² Department of Experimental Clinical and Health Psychology, Ghent University, Ghent, Belgium

³ Research Foundation Flanders, Brussels, Belgium

⁴ Department of Communication Studies, University of Antwerp, Antwerp, Belgium

⁵ School of Health Sciences, University of South Australia, Adelaide, Australia

⁶ Department of Public Health and Primary Care, Ghent University, Ghent, Belgium

⁷ Department of Clinical and Health Psychology, Université Libre de Bruxelles, Brussels, Belgium