title: Adiposity attenuates muscle quality and the adaptive response to resistance exercise in non-obese, healthy adults.
abstract: BACKGROUND
  Emerging data have revealed a negative association between adiposity and muscle quality (MQ). There is a lack of research to examine this interaction among young, healthy individuals, and to evaluate the contribution of adiposity to adaptation after resistance exercise (RE).
  
  
  OBJECTIVE
  The purpose of this investigation was to examine the influence of subcutaneous adipose tissue (SAT) on muscle function among non-obese individuals before and after RE.
  
  
  METHODS
  Analyses included 634 non-obese (body mass index <30 kg m(-2)) subjects (253 males, 381 females; age=23.3 ± 5.2 years). SAT and muscle mass (magnetic resonance imaging-derived SAT and biceps muscle volume), isometric and dynamic biceps strength, and MQ (strength/muscle volume), were analyzed at baseline and after 12 weeks of unilateral RE.
  
  
  RESULTS
  At baseline, SAT was independently associated with lower MQ for males (β=-0.55; P<0.01) and females (β=-0.45; P<0.01), controlling for body mass and age. Adaptation to RE revealed a significant negative association between SAT and changes for strength capacity (β=-0.13; p=0.03) and MQ (β=-0.14; P<0.01) among males. No attenuation was identified among females. Post-intervention SAT remained a negative predictor of MQ for males and females (β=-0.47; P<0.01).
  
  
  CONCLUSIONS
  The findings reveal that SAT is a negative predictor of MQ among non-obese, healthy adults, and that after 12 weeks of progressive RE this association was not ameliorated. Data suggest that SAT exerts a weak, negative influence on the adaptive response to strength and MQ among males.
authors.affiliation: Laboratory for Physical Activity and Exercise Intervention Research, Department of Physical Medicine and Rehabilitation, University of Michigan, Ann Arbor, MI 48108, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Peterson
authors.forename: D
authors.initials: D
authors.lastname: Liu
authors.forename: H
authors.initials: H
authors.lastname: Gordish-Dressman
authors.forename: M J
authors.initials: MJ
authors.lastname: Hubal
authors.forename: E
authors.initials: E
authors.lastname: Pistilli
authors.forename: T J
authors.initials: TJ
authors.lastname: Angelopoulos
authors.forename: P M
authors.initials: PM
authors.lastname: Clarkson
authors.forename: N M
authors.initials: NM
authors.lastname: Moyna
authors.forename: L S
authors.initials: LS
authors.lastname: Pescatello
authors.forename: R L
authors.initials: RL
authors.lastname: Seip
authors.forename: P S
authors.initials: PS
authors.lastname: Visich
authors.forename: R F
authors.initials: RF
authors.lastname: Zoeller
authors.forename: P D
authors.initials: PD
authors.lastname: Thompson
authors.forename: J M
authors.initials: JM
authors.lastname: Devaney
authors.forename: E P
authors.initials: EP
authors.lastname: Hoffman
authors.forename: P M
authors.initials: PM
authors.lastname: Gordon
mesh_terms: D050154:Adiposity; D000328:Adult; D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D055070:Resistance Training; D050151:Subcutaneous Fat / Q000502:physiology*