Informed consent and ethical approvals
When participants agreed to join the study, they completed and signed an informed consent form, in the presence of a trained researcher. Participants received information sheets explaining the study, its aims and procedures, and were encouraged to read and ask any questions they had. They were asked to provide consent for each type of data collection they were involved in. All participants gave their written consent for the use of de-identified data collected during the study to be used in publications and outputs.Ethical approvals for the RCT and the process evaluation were obtained from appropriate country-specific ethics committees (Ethics Committee of the VU University Medical Center [2015.184]; Regional Committees for Medical and Health Research Ethics, Norway [2015/1862]; Ethics Council of the Faculty of Human Kinetics, University of Lisbon [CEFMH 36/2015]; and Ethics Committee at the University of Glasgow College of Medicine, Veterinary and Life Sciences [200140174]). All methods were deployed in this study were performed in accordance with relevant guidelines and regulations.