title: Relative contributions of strength, anthropometric, and body composition characteristics to estimated propulsive force in young male swimmers.
abstract: The purpose of this study was to determine the relative contributions of isokinetic forearm flexion (FLX) and extension (EXT) peak torque (PT) at 180°·s, height (HT), percent body fat (%BF), and fat-free mass (FFM) to the prediction of estimated propulsive force (EPF) and which of these variables should be a focus of training in young male swimmers. Thirty young male swimmers (mean age ± SD = 12.4 ± 2.7 years) volunteered for this study. The subjects were members of local swimming clubs who competed in the front crawl. The swimmers were measured for FLX and EXT PT at 180°·s, HT, body mass (BM), arm muscle area (AMA), arm circumference, triceps skinfold, %BF, and FFM. Arm muscle area was used to calculate EPF. Zero-order correlations and stepwise multiple regression analyses were used to examine the relationships among variables and the relative contributions of FLX, EXT, HT, %BF, and FFM to the prediction of EPF. Forearm flexion PT at 180°·s, EXT, BM, HT, FFM, AMA, and EPF were significantly intercorrelated (r = 0.83-1.00). In addition, 4 variables contributed significantly to the prediction of EPF (standardized regression coefficients = FFM [1.00], FLX [0.92], EXT [-0.62], and HT [-0.35]). Percent body fat did not contribute to any of the stepwise models. These findings suggested that age-related increases in HT and FFM, as well as training for increases in FLX and EXT strength may improve propulsive force and swimming performance in young male swimmers.
authors.affiliation: 1Department of Nutrition and Health Sciences, Human Performance Laboratory, University of Nebraska-Lincoln, Lincoln, Nebraska; and 2Department of Oral Biology, College of Dentistry, University of Nebraska Medical Center, Lincoln, Nebraska.
authors.forename: Kristen C
authors.initials: KC
authors.lastname: Cochrane
authors.forename: Terry J
authors.initials: TJ
authors.lastname: Housh
authors.forename: Cory M
authors.initials: CM
authors.lastname: Smith
authors.forename: Ethan C
authors.initials: EC
authors.lastname: Hill
authors.forename: Nathaniel D M
authors.initials: ND
authors.lastname: Jenkins
authors.forename: Glen O
authors.initials: GO
authors.lastname: Johnson
authors.forename: Dona J
authors.initials: DJ
authors.lastname: Housh
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Schmidt
authors.forename: Joel T
authors.initials: JT
authors.lastname: Cramer
mesh_terms: D050154:Adiposity; D000293:Adolescent; D001827:Body Height; D001835:Body Weight; D001837:Body Weights and Measures; D002648:Child; D005542:Forearm / Q000502:physiology; D006801:Humans; D008297:Male; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000502:physiology*; D012885:Skinfold Thickness; D013550:Swimming / Q000502:physiology*; D019415:Torque