title: The Influence of Maturation on Sprint Performance in Boys over a 21-Month Period.
abstract: This study examined how the characteristics of maximal overground sprint performance are affected by the period of peak height velocity (PHV) in boys.
  
  
  
  One hundred eighty-nine school-age boys completed two assessments of maximal sprint performance, separated by a 21-month period. Kinematic characteristics of sprint performance were collected during a 30-m sprint using a floor-level optical measurement system, with modeled force and stiffness characteristics also calculated. Participants were grouped according to maturation using a noninvasive predictive equation. Individuals whose maturity offset was <-0.5 yr in both assessments were classed as "pre-PHV" (n = 67), whereas those whose maturity offset developed from <-0.5 to >0.5 yr in test two were classed as "pre-to-post PHV" (n = 39). Participants with a maturity offset between >-0.5 and <0.5 yr at test 2 were removed from analysis (n = 67) to ensure that the entire pre-to-post-PHV group had experienced the PHV spurt.
  
  
  
  The pre-to-post-PHV group experienced significantly greater increases in speed (10.4% vs 5.6%) and relative vertical stiffness (12.1% vs 5.6%) compared with the pre-PHV group. Step frequency declined (-2.4%) and contact time increased (2.3%) in the pre-PHV group, whereas step frequency increased (2.7%) and contact time decreased (-3.6%) in the pre-PHV to post-PHV group. Changes in relative measures of vertical stiffness, maximal force, and leg stiffness accounted for 79% and 83% of the changes in speed between assessments for pre-PHV and pre-to-post-PHV groups, respectively.
  
  
  
  As boys experience PHV, there are greater increases in maximal sprint speed compared with those who remain pre-PHV. Furthermore, measures of relative stiffness and relative maximal force appear to exert an important influence on the development of maximal sprint speed in boys, regardless of maturity.
authors.affiliation: 1Youth Physical Development Unit, Cardiff School of Sport, Cardiff Metropolitan University, Cardiff, UNITED KINGDOM; 2Sports Performance Research Institute, AUT University, Auckland, NEW ZEALAND; and 3School of Exercise, Biomedical and Health Science, Edith Cowan University, Perth, AUSTRALIA.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Meyers
authors.forename: Jon L
authors.initials: JL
authors.lastname: Oliver
authors.forename: Michael G
authors.initials: MG
authors.lastname: Hughes
authors.forename: Rhodri S
authors.initials: RS
authors.lastname: Lloyd
authors.forename: John B
authors.initials: JB
authors.lastname: Cronin
mesh_terms: D000293:Adolescent; D054874:Athletic Performance / Q000502:physiology*; D001696:Biomechanical Phenomena; D001827:Body Height; D002648:Child; D006801:Humans; D007866:Leg / Q000502:physiology; D008137:Longitudinal Studies; D008297:Male; D012420:Running / Q000502:physiology*; D012741:Sexual Maturation / Q000502:physiology*