title: Association of physical activity with muscular strength and fat-free mass in adolescents: the HELENA study.
abstract: The objective of this study is to analyse the association of objectively assessed physical activity (PA) with muscular strength and fat-free mass in adolescents, and to determine whether meeting the current PA recommendations is associated with higher levels of muscular strength and fat-free mass. The present cross-sectional study comprised 363 Spanish adolescents (180 females) aged 12.5-17.5 years. PA was assessed by accelerometry and expressed as average PA (counts/min), and min/day of inactive, light, moderate, vigorous and moderate to vigorous PA (MVPA). MVPA was dichotomized into < 60 min/day and > or = 60. Upper body muscular strength was measured with the handgrip strength test, and lower body muscular strength was measured with the standing broad jump, squat jump, counter movement jump and Abalakov tests. Fat-free mass was measured by DXA. We observed positive associations between vigorous PA and all the lower body muscular strength tests except for the counter movement jump in males. PA was not associated with fat-free mass in both males and females. Male adolescents engaged in at least 60 min/day MVPA performed better in the standing broad jump test. In conclusion, the findings of the present study suggest that only vigorous PA is associated with muscular strength, particularly lower-body muscular strength in male adolescents.
authors.affiliation: Growth, Exercise, Nutrition, and Development Research Group, Universidad de Zaragoza, Corona de Aragón 42, 2nd floor, 50009, Zaragoza, Spain. dmoliner@unizar.es
authors.forename: Diego
authors.initials: D
authors.lastname: Moliner-Urdiales
authors.forename: Francisco B
authors.initials: FB
authors.lastname: Ortega
authors.forename: Germán
authors.initials: G
authors.lastname: Vicente-Rodriguez
authors.forename: Juan P
authors.initials: JP
authors.lastname: Rey-Lopez
authors.forename: Luis
authors.initials: L
authors.lastname: Gracia-Marco
authors.forename: Kurt
authors.initials: K
authors.lastname: Widhalm
authors.forename: Michael
authors.initials: M
authors.lastname: Sjöström
authors.forename: Luis A
authors.initials: LA
authors.lastname: Moreno
authors.forename: Manuel J
authors.initials: MJ
authors.lastname: Castillo
authors.forename: Jonatan R
authors.initials: JR
authors.lastname: Ruiz
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D000293:Adolescent; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*