title: Seasonal changes in stress indicators in high level football.
abstract: This study aimed at describing changes in stress and performance indicators throughout a competitive season in high level football. 15 players (19.5±3.0 years, 181±5 cm, 75.7±9.0 kg) competing under professional circumstances were tested at baseline and 3 times during the season 2008/09 (in-season 1, 2, 3). Testing consisted of the Recovery-Stress Questionnaire for Athletes (Total Stress and Recovery score), vertical jump tests (counter movement and drop jump (DJ)), and a maximal ramp-like running test. Average match exposure was higher during a 3-weeks period prior to in-season 3 compared to in-season 1 and 2 (1.5 vs. 1 h/week, p=0.05). Total Stress score was elevated at in-season 1 and 2 compared to baseline (p<0.01) with a further increase at in-season 3 (p<0.03; generalized eta squared (η(2)(g))=0.37). Total Recovery score was decreased at in-season 1 and 3 compared to baseline (p<0.05; η(2)(g)=0.21). Maximal running velocity (V(max)) and jumping heights were not significantly affected (η(2)(g)≤0.04). Changes in DJ height and V (max) between baseline and in-season 3 were correlated with the corresponding changes in Total Stress score (r=-0.55 and r=-0.61, p<0.03). Usual match exposure during a professional football season does not induce relevant changes in performance indicators. Accumulated stress and a lack of recovery towards the end of a season might be indicated by psychometric deteriorations.
authors.affiliation: Institute of Sports and Preventive Medicine, Saarland University, Saarbrücken, Germany. o.faude@mx.uni-saarland.de
authors.forename: O
authors.initials: O
authors.lastname: Faude
authors.forename: M
authors.initials: M
authors.lastname: Kellmann
authors.forename: T
authors.initials: T
authors.lastname: Ammann
authors.forename: R
authors.initials: R
authors.lastname: Schnittker
authors.forename: T
authors.initials: T
authors.lastname: Meyer
mesh_terms: D000293:Adolescent; D054874:Athletic Performance / Q000502:physiology*; D005221:Fatigue; D006801:Humans; D008297:Male; D011594:Psychometrics; D012621:Seasons; D012916:Soccer / Q000502:physiology*; D013312:Stress, Physiological / Q000502:physiology*; D011795:Surveys and Questionnaires; D055815:Young Adult