Can motivation and overtraining predict burnout in professional soccer athletes in different periods of the season?

Are motivation and overtraining reliable predictors of burnout in male professional soccer athletes over the course of the season? To answer this question, 32 Brazilian athletes from the same team (age: 24.16 ± 4.58 years) participated in this study and completed the following questionnaires during different periods of the season (n = 1 baseline, n = 2 preparatory, and n = 5 competitive): the Sport Motivation Scale (SMS I), the Recovery-Stress Questionnaire for Athletes (RESTQ-Sport 76), and the Athlete Burnout Questionnaire (ABQ). The results indicated positive and negative as well as moderate and strong associations among the dimensions of motivation, overtraining and burnout. Regression analysis was used to estimate three models during the season (baseline/preparatory, baseline/competitive, and preparatory/competitive). Model 1 showed that the amotivation dimension predicts emotional and physical exhaustion (SEE = 0.39; p = 0.001; = 0.38) and total burnout (SEE = 0.25; p = 0.001; = 0.32). Model 2 indicated that amotivation predicts emotional and physical exhaustion (SEE = 0.32; p = 0.002; = 0.24) and total burnout (SEE = 0.40; p = 0.001; = 0.35). Model 3 evidenced that amotivation and sport-specific stress predict emotional and physical exhaustion (SEE = 0.19; p = 0.001; = 0.73) and total burnout (SEE = 0.27; p = 0.001; = 0.72). In conclusion, it was verified that the dimensions of amotivation and sport-specific stress are effective markers to predict burnout in the preparatory and competitive periods.