What Are the Load and Wellness of Young Second-Team Football Players When Transitioning to the First Team? A Comparison of 2 Consecutive Preseasons

To compare the load and wellness of second-team academy football players during a first-team preseason with those of first-team players and those of their previous second-team preseason. Athletic Club's first- (n = 10) and second-team (n = 9) players were prospectively followed during the 2019-20 first- and second-team and 2020-21 first-team preseasons. Weekly external and internal loads and average wellness z-scores (fatigue, sleep quality, muscle soreness, stress, and mood) were compared between preseasons and teams. While training together during the 2020-21 preseason, second-team players performed more decelerations 3 m/s2 (large), and decelerations