title: Lower extremity power in female soccer athletes: a pre-season and in-season comparison.
abstract: OBJECTIVE
  Lower extremity power is an important physical capacity of a soccer athlete. Power represents, and can be modified by, the training of strength and speed. Pre-season and in-season training differs in the relative emphasis on these two quantities. It is nevertheless desirable that the mechanical power remain the same or become higher during the in-season period. The purpose of this study was to identify changes in quantities related to "explosive strength" and to check whether, in collegiate female soccer players, pre- and inseason lower extremity power will remain unaltered.
  
  
  METHODS
  Twenty collegiate female soccer players, representing all field positions, participated. Lower extremity power was assessed by a series of drop jumps executed from four different heights (15, 30, 45, and 60 cm). Mechanical power was calculated using subject's mass, jump height, and acceleration due to gravity. This value was further normalized by body mass of each athlete to obtain the relative (or normalized) mechanical power.
  
  
  RESULTS
  The normalized lower extremity mechanical power was highest when landing from the 30 cm height for both pre- and inseason periods. However, contrary to expectations, it turned out lower during the in-season than during the pre-season test, even though no significant differences were found between the corresponding jump heights.
  
  
  CONCLUSIONS
  It is concluded that altered, perhaps inadequate, training strategies were employed during the in-season period. Besides, advantages of adding the relative mechanical power as a season readiness indicator are underlined compared with relying on the jump height alone.
authors.affiliation: Department of Biomechanics, University School of Physical Education, Wrocław, Poland.
authors.forename: Bogdan
authors.initials: B
authors.lastname: Pietraszewski
authors.affiliation: Department of Biomechanics, University School of Physical Education, Wrocław, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Siemieński
authors.affiliation: Department of Biomechanics, University School of Physical Education, Wrocław, Poland.
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Bober
authors.affiliation: Department of Biomechanics, University School of Physical Education, Wrocław, Poland.
authors.forename: Artur
authors.initials: A
authors.lastname: Struzik
authors.affiliation: Department of Biomechanics, University School of Physical Education, Wrocław, Poland.
authors.forename: Alicja
authors.initials: A
authors.lastname: Rutkowska-Kucharska
authors.affiliation: Department of Team Sport Games, University School of Physical Education, Wrocław, Poland.
authors.forename: Jarosław
authors.initials: J
authors.lastname: Nosal
authors.affiliation: Department of Team Sport Games, University School of Physical Education, Wrocław, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Rokita
mesh_terms: D056352:Athletes; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007866:Leg / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology; D012621:Seasons; D012916:Soccer; D055815:Young Adult