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 (p= 0.04, effect size [ES] ES1-2= 0.15-0.06, ES2-3= 0.24) from T1 to T3. YYIR1 performance improved significantly from T1 to T2 and declined significantly from T2 to T3 (p= 0.001, ES1-2= 0.24, ES2-3= -2.54). Mean RSSA performance was significantly higher (p= 0.019, ES1-2= -0.47, ES2-3= 1.15) in T3 compared with T2 and T1. Best RSSA performance was significantly higher in T3 when compared with T2 and T1 (p= 0.006, ES2-3= 0.47, ES1-2= -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:p= 0.03, ES3-2= -0.51, ES3-1= -0.51, T/C:p= 0.017, ES3-2= -1.1, ES3-1= -1.07). Significant decreases were found for the vigor scores in T3 when compared to T2 and T1 (p= 0.002, ES1-2= 0.31, ES3-2= -1.25). A significant increase was found in fatigue scores in T3 as compared to T1 and T2 (p= 0.002, ES1-2= 0.43, ES2-3= 0.81). A significant increase was found from T1 < T2 < T3 intension score (p= 0.002, ES1-2= 1.1, ES2-3= 0.2) and anger score (p= 0.03, ES1-2= 0.47, ES2-3= 0.33) over the study period. Total mood disturbance increased significantly (p= 0.02, ES1-2= 0.91, ES2-3= 1.1) from T1 to T3. Between T1-T2, significant relationships were observed between workload and changes in T (r= 0.66,p= 0.003), and T/C ratio (r= 0.62,p= 0.01). There were significant relationships between performance in RSSA(best)and training load parameters (workload:r= 0.52,p= 0.03; monotony:r= 0.62,p= 0.01; strain:r= 0.62,p= 0.009). Between T2-T3, there was a significant relationship between Delta% of total mood disturbance and Delta% of YYIR1 (r= -0.54;p= 0.04), RSSA(best)(r= 0.58,p= 0.01), SJ (r= -0,55,p= 0.01), T (r= 0.53;p= 0.03), and T/C (r= 0.5;p= 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.