title: Effects of excess body mass on strength and fatigability of quadriceps in postmenopausal women.
abstract: OBJECTIVE
  Obesity is a major public health problem leading to, among other things, reduced functional capacity. Moreover, obesity-related declines in functional capacity may be compounded by the detrimental consequences of menopause. The aim of this study was to understand the potential effects of excess body mass on measures of functional capacity in postmenopausal women.
  
  
  METHODS
  Forty-five postmenopausal women aged 50 to 60 years were divided into two groups according to body mass index (BMI): obese (BMI, ≥ 30 kg/m(2); n = 19) and nonobese (BMI, 18.5-29.9 kg/m(2); n = 26). To determine clinical characteristics, body composition, bone mineral density, and maximal exercise testing was performed, and a 3-day dietary record was estimated. To assess quadriceps function, isokinetic exercise testing at 60° per second (quadriceps strength) and at 300° per second (quadriceps fatigue) was performed.
  
  
  RESULTS
  The absolute value of the peak torque was not significantly different between the groups; however, when the data were normalized by body mass and lean mass, significantly lower values were observed for obese women compared with those in the nonobese group (128% ± 25% vs 155% ± 24% and 224% ± 38% vs 257% ± 47%, P < 0.05). The fatigue index did not show any significant difference for either group; however, when the data were normalized by the body mass and lean mass, significantly lower values were observed for obese women (69% ± 16% vs 93% ± 18% and 120% ± 25% vs. 135% ± 23%, P < 0.01).
  
  
  CONCLUSIONS
  Our results show that despite reduced muscle force, the combination of obesity and postmenopause may be associated with greater resistance to muscle fatigue.
authors.affiliation: Optics Group from Instituto de Física de São Carlos, University of São Paulo, São Paulo, Brazil. fer.nanda.rp@hotmail.com
authors.forename: Fernanda Rossi
authors.initials: FR
authors.lastname: Paolillo
authors.forename: Juliana Cristina
authors.initials: JC
authors.lastname: Milan
authors.forename: Patrícia de Godoy
authors.initials: Pde G
authors.lastname: Bueno
authors.forename: Alessandra Rossi
authors.initials: AR
authors.lastname: Paolillo
authors.forename: Audrey
authors.initials: A
authors.lastname: Borghi-Silva
authors.forename: Nivaldo Antonio
authors.initials: NA
authors.lastname: Parizotto
authors.forename: Ross
authors.initials: R
authors.lastname: Arena
authors.forename: Cristina
authors.initials: C
authors.lastname: Kurachi
authors.forename: Vanderlei Salvador
authors.initials: VS
authors.lastname: Bagnato
mesh_terms: D001823:Body Composition; D015992:Body Mass Index; D015519:Bone Density; D004032:Diet; D005080:Exercise Test; D005260:Female; D006801:Humans; D008875:Middle Aged; D018763:Muscle Fatigue; D053580:Muscle Strength; D009765:Obesity / Q000503:physiopathology*; D010807:Physical Endurance; D017698:Postmenopause; D052097:Quadriceps Muscle / Q000503:physiopathology*; D019415:Torque; D016474:Weight-Bearing / Q000502:physiology