Vai trò của thể lực trong quần vợt trực tiếp: Nghiên cứu trường hợp vận động viên chuyên nghiệp

[Write an engaging introduction to the essay here. It should set the stage for the discussion about the role of physical fitness in professional tennis, hinting at the importance of this topic for the success of professional players.]

[Write a conclusion that summarizes the key points discussed in the essay. It should reiterate the significance of physical fitness in professional tennis and its impact on a player's performance, injury prevention, and career longevity.]