The Interplay Between Plasma Hormonal Concentrations, Physical Fitness, Workload and Mood State Changes to Periods of Congested Match Play in Professional Soccer Players.

Background: The regular assessment of hormonal and mood state parameters in professional soccer are proposed as good indicators during periods of intense training and/or competition to avoid overtraining.

Objective: The aim of this study was to analyze hormonal, psychological, workload and physical fitness parameters in elite soccer players in relation to changes in training and match exposure during a congested period of match play.

Methods: Sixteen elite soccer players from a team playing in the first Tunisian soccer league were evaluated three times (T1, T2, and T3) over 12 weeks. The non-congested period of match play was from T1 to T2, when the players played 6 games over 6 weeks. The congested period was from T2 to T3, when the players played 10 games over 6 weeks. From T1 to T3, players performed the Yo-Yo intermittent recovery test level 1 (YYIR1), the repeated shuttle sprint ability test (RSSA), the countermovement jump test (CMJ), and the squat jump test (SJ). Plasma Cortisol (C), Testosterone (T), and the T/C ratio were analyzed at T1, T2, and T3. Players had their mood dimensions (tension, depression, anger, vigor, fatigue, confusion, and a Total Mood Disturbance) assessed through the Profile of Mood State questionnaire (POMS). Training session rating of perceived exertion (sRPE) was also recorded on a daily basis in order to quantify internal training load and elements of monotony and strain.

Results: Significant performance declines (T1 < T2 < T3) were found for SJ performance ( = 0.04, effect size [ES] ES = 0.15-0.06, ES = 0.24) from T1 to T3. YYIR1 performance improved significantly from T1 to T2 and declined significantly from T2 to T3 ( = 0.001, ES = 0.24, ES = -2.54). Mean RSSA performance was significantly higher ( = 0.019, ES = -0.47, ES = 1.15) in T3 compared with T2 and T1. Best RSSA performance was significantly higher in T3 when compared with T2 and T1 ( = 0.006, ES = 0.47, ES = -0.56), but significantly lower in T2 when compared with to T1. T and T/C were significantly lower in T3 when compared with T2 and T1 (T: = 0.03, ES = -0.51, ES = -0.51, T/C: = 0.017, ES = -1.1, ES = -1.07). Significant decreases were found for the vigor scores in T3 when compared to T2 and T1 ( = 0.002, ES = 0.31, ES = -1.25). A significant increase was found in fatigue scores in T3 as compared to T1 and T2 ( = 0.002, ES = 0.43, ES = 0.81). A significant increase was found from T1 < T2 < T3 intension score ( = 0.002, ES = 1.1, ES = 0.2) and anger score ( = 0.03, ES = 0.47, ES = 0.33) over the study period. Total mood disturbance increased significantly ( = 0.02, ES = 0.91, ES = 1.1) from T1 to T3. Between T1-T2, significant relationships were observed between workload and changes in T ( = 0.66, = 0.003), and T/C ratio ( = 0.62, = 0.01). There were significant relationships between performance in RSSA and training load parameters (workload: = 0.52, = 0.03; monotony: = 0.62, = 0.01; strain: = 0.62, = 0.009). Between T2-T3, there was a significant relationship between Δ% of total mood disturbance and Δ% of YYIR1 ( = -0.54; = 0.04), RSSA ( = 0.58, = 0.01), SJ ( = -0,55, = 0.01), T ( = 0.53; = 0.03), and T/C ( = 0.5; = 0.04).

Conclusion: An intensive period of congested match play significantly compromised elite soccer players' physical and mental fitness. These changes were related to psychological but not hormonal parameters; even though significant alterations were detected for selected measures. Mood monitoring could be a simple and useful tool to determine the degree of preparedness for match play during a congested period in professional soccer.