AUTHOR=Wang Jian , Xu Qi TITLE=Single-session upper limb plyometric training is as effective as two sessions for improving muscle strength, power, and serve velocity in male youth tennis players: a randomized parallel controlled study JOURNAL=Frontiers in Psychology VOLUME=16 YEAR=2025 URL=https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2025.1539739 DOI=10.3389/fpsyg.2025.1539739 ISSN=1664-1078