An online training program was effective on improving physical performance and body composition in U20 soccer players during the COVID-19 quarantine

Elite sports were severely affected by COVID-19. Prolonged periods of detraining and staying at home have a negative influence on athletes’ physical conditioning. Therefore, is recommended for most athletes keep training at home to reduce the negative side effects of detraining. This study aimed to verify the effects of a 15-week online training intervention during a pandemic quarantine in body composition and physical capacity of highly trained soccer players. Sixteen male under-20 soccer players were assessed after the first period of COVID-19 quarantine (March 2020 to September 2020; 170 days), and after the second period of COVID-19 quarantine (November 2020 to February 2021, 107 days). Body composition, vertical jump height, hamstring maximum strength and aerobic capacity were assessed. The online training program was performed during the second lockdown. In comparison with first pre assessments, results showed that fat mass (-0.95 ± 1.27), free fat mass (1.22 ± 1.19), squat jump height (5.36 ± 1.99) and counter movement jump (3.19 ± 3.77) were significantly improved (p < 0.05). However, there were no significant changes in total body mass, hamstring eccentric strength, and Yo-Yo IR1 after online training (p > 0.05). In summary, the findings of this study highlight the importance of carrying out an online training program during a period of absence from traditional soccer training, in order to maintain the level of physical capacities of youth soccer players.