title: Characteristics associated with running performance in young boys.
abstract: The purpose of the study was to replicate and extend the investigation of characteristics associated with running performance in young boys. Two groups of 10-year-old males were studied. One group (A runners) consisted of subjects who placed above the 55th percentile on a 1.6-km run; a second group (B runners) included children who placed below the 45th percentile. No significant (P greater than 0.05) between-group mean differences were noted for leg length, skeletal age, body coordination, or running economy (the aerobic demands at steady-state submaximal speeds). Significant (P less than 0.05) between-group mean differences were found for maximal aerobic power (A, 55.1; B, 48.6 ml X min-1 X kg-1), two-site skinfold sum (A, 15.2; B, 22.7 mm), and maximal sprinting speed (A, 359.7; B, 341.1 m X min-1). When compared with A runners, B runners performed 9-min runs at a higher percentage of their maximal speed (A, 58.0; B, 51.6%), required a higher VO2 to maintain this pace (A, 48.5; B, 40.8 ml X min-1 X kg-1), and exhibited higher 4.5-min post-run blood lactate levels (A, 9.1; B, 6.7 mM X 1(-1). It was concluded that post-exercise blood lactate levels are associated, and maturity and body composition are not associated with differences in distance-running performance in boys of this age.
mesh_terms: D000365:Age Determination by Skeleton; D002648:Child; D006801:Humans; D007773:Lactates / Q000097:blood; D007866:Leg / Q000033:anatomy & histology; D008297:Male; D010101:Oxygen Consumption; D011597:Psychomotor Performance / Q000502:physiology; D012420:Running; D012885:Skinfold Thickness
chemical_list: D007773:Lactates