an extensive search of MEDLINE, Sports DISCUS, CINAHL, Web of Science, and Scopus databases in April-May 2018 was conducted and identified 646 studies. 
MEDLINE
an extensive search of MEDLINE, Sports DISCUS, CINAHL, Web of Science, and Scopus databases in April-May 2018 was conducted and identified 646 studies. 
Sports DISCUS
an extensive search of MEDLINE, Sports DISCUS, CINAHL, Web of Science, and Scopus databases in April-May 2018 was conducted and identified 646 studies. 
CINAHL
an extensive search of MEDLINE, Sports DISCUS, CINAHL, Web of Science, and Scopus databases in April-May 2018 was conducted and identified 646 studies. 
Web of Science
an extensive search of MEDLINE, Sports DISCUS, CINAHL, Web of Science, and Scopus databases in April-May 2018 was conducted and identified 646 studies. 
Scopus