title: Effect of cold-water immersion on skeletal muscle contractile properties in soccer players.
abstract: OBJECTIVE
  This study was designed to analyze changes in muscle response after cold-water immersion.
  
  
  METHODS
  The vastus lateralis of the dominant leg was analyzed in 12 professional soccer players from the Spanish 2nd Division B using tensiomyography, before and after four cold-water immersions at 4°C lasting 4 mins each. Core temperature, skin temperature, and heart rate were monitored.
  
  
  RESULTS
  A significant interaction (P ≤ 0.05) was found in muscle deformation between control conditions (5.12 ± 2.27 mm) and (1) immersion 3 (3.64 ± 2.27 mm) and (2) immersion 4 (3.38 ± 1.34 mm). A steady decrease was also observed in response velocity (immersion 1, -7.3%; immersion 2, -25.9%; immersion 3, -30.0%; immersion 4, -36.6%) and contraction velocity (immersion 1, -11.5%; immersion 2, -22.1%; immersion 3, -35.0%; immersion 4, -41.9%), with statistically significant differences (P ≤ 0.05) in relation to the reference values commencing with the third immersion. No significant differences were found between control conditions in subsequent exposures to cold water for the values of response time and contraction time. Sustained time and reaction time showed an increase during repeated exposures and with longer exposure time, although the increase was not statistically significant.
  
  
  CONCLUSIONS
  This study shows that repeated cold-water immersions (4 × 4 mins at 4°C) cause considerable alterations to muscle behavior. These alterations significantly affect the state of muscles and their response capacity, particularly in relation to muscle stiffness and muscle contraction velocity.
authors.affiliation: Sports Training Analysis and Planning Laboratory, University of Las Palmas de Gran Canaria (ULPGC), Las Palmas de Gran Canaria, Madrid, Spain.
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: García-Manso
authors.forename: Darío
authors.initials: D
authors.lastname: Rodríguez-Matoso
authors.forename: David
authors.initials: D
authors.lastname: Rodríguez-Ruiz
authors.forename: Samuel
authors.initials: S
authors.lastname: Sarmiento
authors.forename: Yves
authors.initials: Y
authors.lastname: de Saa
authors.forename: Javier
authors.initials: J
authors.lastname: Calderón
mesh_terms: D000328:Adult; D056352:Athletes; D003080:Cold Temperature; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007101:Immersion; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012881:Skin Temperature / Q000502:physiology; D012916:Soccer; D013997:Time Factors