title: Relationships between repeated sprint ability, mechanical parameters, and blood metabolites in professional soccer players.
abstract: This study analyzed the acute metabolic and mechanical responses to a specific repeated sprint ability (RSA) test. Eighteen male professional soccer players from a team of the First Division of Spanish National League participated. A 12 × 30-m RSA test with 30-second recovery together with countermovement jump test (CMJ) pre a post RSA test was performed. Mechanical responses (i.e., height performance in CMJ and speed loss) and metabolic responses (i.e., blood lactate and ammonia concentrations) were measured before and after exercise. A related sample t-test was used to analyze CMJ height pre-post changes as well as to compare pre- and post-exercise lactate and ammonia levels. Countermovement jump height loss pre-post session (8%) was significant, and fatigue, measured as CMJ height loss, was strongly correlated to lactate (r = 0.97; p < 0.001) and ammonia (r = 0.92; p < 0.001) for all players. The relationships between the variables studied were determined by calculating the Pearson correlation coefficients. The metabolic stress developed during the effort can be estimated by controlling CMJ because of the high correlation between CMJ and blood lactate and ammonia concentrations. The high correlations found between mechanical (speed and CMJ height losses) and metabolic (lactate and ammonia) measures of fatigue highlight the utility and validity of using CMJ to monitor training load and quantify objectively neuromuscular fatigue during RSA.
authors.affiliation: 1Department of Physical Education and Sport, University of Jaen, Jaen, Spain; 2Department of Physical Education and Sport, Catholic University of Murcia, Murcia, Spain; 3Faculty of Education, Complutense University of Madrid, Madrid, Spain; 4Department of Statistics and Operations Research, University of Jaen, Jaen, Spain; and 5Department of Physical Education and Sport Pablo de Olavide, University of Seville, Seville, Spain.
authors.forename: Jose A
authors.initials: JA
authors.lastname: Morcillo
authors.forename: Pedro
authors.initials: P
authors.lastname: Jiménez-Reyes
authors.forename: Victor
authors.initials: V
authors.lastname: Cuadrado-Peñafiel
authors.forename: Emilio
authors.initials: E
authors.lastname: Lozano
authors.forename: Manuel
authors.initials: M
authors.lastname: Ortega-Becerra
authors.forename: Juan
authors.initials: J
authors.lastname: Párraga
mesh_terms: D000328:Adult; D000641:Ammonia / Q000097:blood; D054874:Athletic Performance / Q000502:physiology*; D005080:Exercise Test; D005221:Fatigue / Q000097:blood / Q000503:physiopathology*; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D018763:Muscle Fatigue; D012420:Running / Q000502:physiology*; D012916:Soccer / Q000502:physiology*; D013312:Stress, Physiological; D055815:Young Adult
chemical_list: D019344:Lactic Acid; D000641:Ammonia