Funding for this research was provided by:
Stockholms Läns Landsting (ALF)
Centrum for Idrottsforskning (na)
European union (2006120)
Folksam (na)
Karolinska Institutet (SFO-V fellowship)
Article History
Received: 5 June 2019
Accepted: 6 November 2019
First Online: 9 December 2019
Ethics approval and consent to participate
: The study was approved by the ethics committee at the Karolinska Institutet (Dnr 378/02, 2012/707 31/1, 2015 1578/32). All participants provided written informed consent, and all procedures were in accordance with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Not applicable.
: The authors declare that they have no competing interests.