Effects of a Short Half-Time Re-Warm-Up Program on Matches Running Performance and Fitness Test Performance of Male Elite Youth Soccer Players  
[PERSON], [PERSON]\({}^{\circledR}\)  
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running performance in the initial minutes of the second half in comparison with the first half. However, there are studies that have investigated the change in running performance between the two halves. In these studies, some observed a decrease in performance [7; 8; 9], others found no differences [10; 11], and others noticed an increase in performance [12; 13]. This decrease in performance in the first few minutes after half-time can be attributed to the limited recovery from the first-half effort, the lack of preparation for the second half, and other factors such as internal motivation and tactical instructions.  
Because this phenomenon has been observed by sports scientists for years, attempts have been made to limit these negative effects. For this purpose, programs are proposed that can be implemented in order to limit the decrease in body temperature and performance in general as described in a recent review [14]. More specifically, re-warm-up programs have been used that include cycling, soccer actions, running, agility, etc. [2; 15; 16; 17; 18]. [PERSON] et al. (2004) [2] studied the beneficial effect of a 7 min re-warm-up at half-time on sprint performance during soccer matches. In a more recent study, [PERSON] et al. (2017) [15] compared the effects of different re-warm-up programs on the physical performance of soccer players. From the above studies, we understand that there is a great variety of exercises used for this purpose. They also vary in methodology, with some studies assessing the running performance of soccer players during real soccer matches [2; 16] while others evaluated performance in simulation tests [18; 19]. In a study carried out on soccer players of developmental age [17], they observed that the implementation of active re-warm-up programs at half-time limited the decrement in endurance performance during the second half. However, it should be mentioned that the study evaluated running performance in a particular running drill and not in a real soccer match.  
In previous studies, it has been reported that only 58% of Premier League and Championship coaches implement such programs on the pitch or in specially designated areas and 63% say the main reason they do not use them is lack of time [20]. Therefore, various programs that were suggested to last approximately seven minutes seemed to be effective in maintaining body temperature and performance on various fitness tests. However, they were not realistic as they took a great deal of time. As a result, coaches did not apply them. Moreover, studies have investigated the effect of shorter programs (<7 min) [21]. From the review of the literature, it seems that studies investigating such warm-up programs are limited [21].  
Thus, the purpose of the study was to investigate the effect of a very short (three-minute) re-warm-up program on the performance of high-level young soccer players in fitness tests and their running performance during soccer league matches. Considering previous studies that have reported maintaining the performance of football players after a re-warm-up compared to passive rest, we assume that both the running performance of the players during the matches and their performance in the fitness tests will be higher after the implementation of the re-warm-up program in comparison to the passive rest.