AUTHOR=Dai Zhidong , Zheng Tianchen , Li Rongzhi TITLE=The U-shaped effect of coach-athlete attachment on athlete engagement: the mediating role of thriving and the moderating role of mental toughness JOURNAL=Frontiers in Psychology VOLUME=16 YEAR=2025 URL=https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2025.1544860 DOI=10.3389/fpsyg.2025.1544860 ISSN=1664-1078