Funding for this research was provided by:
Shanghai Pujiang Program (17PJC085)
Shanghai Education Scientific Research Project (C160030)
Science and Technology Commission of Shanghai Municipality (18080503100)
Article History
Received: 21 April 2018
Accepted: 15 April 2019
First Online: 25 April 2019
Ethics approval and consent to participate
: The ethics committee in Shanghai university of Sport approved this study. Each participant had signed informed consent before the face-to-face interview.
: Not applicable.
: The authors declare that they have no competing interests.
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