title: Muscular fitness as a mediator of quality cardiopulmonary resuscitation.
abstract: BACKGROUND
  It has been hypothesized that body mass index (BMI) and muscle strength (MS) of the rescuers are predictors of adequate external chest compressions (ECC). The aims of this study were: (a) to analyze, in college students, the relationship between BMI and MS with adequate ECC parameters; and (b) to examine whether the association between BMI and adequate ECC parameters is mediated by MS.
  
  
  METHODS
  A cross-sectional analysis of the evaluation of a CPR performance test involving students (n=63). We determined BMI and MS. After previous training, participants performed cardiopulmonary resuscitation on a mannequin for 20 minutes. PROCESS macro developed by Preacher and Hayes was used to assess whether the association between BMI and ECC was mediated by MS.
  
  
  RESULTS
  Underweight subjects achieved lower results than those with normal weight and overweight/obese in several dependent variables including: correct compression depth (P<.001) and adequate ECC (P<.001). This differences remained after adjusting for muscle strength except for the compression rate (P=.053). Moreover, participants in the low MS quartile were lower in both correct compression depth (P=.001) and adequate ECC (P<.001) than participants in the medium/high quartile after adjusting for confounding variables. The effect of BMI on adequate ECC was partially mediated by MS. Similar results were obtained in the analysis of the mediator role of MS in the relationship between BMI and correct compression depth.
  
  
  CONCLUSIONS
  The ability to provide adequate ECC is influenced by the rescuer's MS. Rescuers should be advised to exercise arm strength to improve the quality of CPR.
authors.affiliation: School of Nursing, University of Castilla-La Mancha, Albacete, Spain. Electronic address: angel.lopez@uclm.es.
authors.forename: Angel
authors.initials: A
authors.lastname: López-González
authors.affiliation: University of Castilla-La Mancha, Health and Social Research Centre, Cuenca, Spain. Electronic address: mairena.sanchez@uclm.es.
authors.forename: Mairena
authors.initials: M
authors.lastname: Sánchez-López
authors.affiliation: Laboratorio de Ciencias de la Actividad Física, el Deporte y la Salud, Facultad de Ciencias Médicas, Universidad de Santiago de Chile, USACH, Chile. Electronic address: agarciah@uautonoma.cl.
authors.forename: Antonio
authors.initials: A
authors.lastname: Garcia-Hermoso
authors.affiliation: University of Castilla-La Mancha, Health and Social Research Centre, Cuenca, Spain. Electronic address: leman_1988@hotmail.com.
authors.forename: Jaime
authors.initials: J
authors.lastname: López-Tendero
authors.affiliation: University of Castilla-La Mancha, Health and Social Research Centre, Cuenca, Spain. Electronic address: Joseba.rabanales@uclm.es.
authors.forename: Joseba
authors.initials: J
authors.lastname: Rabanales-Sotos
authors.affiliation: University of Castilla-La Mancha, Health and Social Research Centre, Cuenca, Spain; Universidad Autónoma de Chile, Facultad de Ciencias de la Salud, Talca, Chile. Electronic address: vicente.martinez@uclm.es.
authors.forename: Vicente
authors.initials: V
authors.lastname: Martínez-Vizcaíno
mesh_terms: D000328:Adult; D015992:Body Mass Index; D016887:Cardiopulmonary Resuscitation / Q000592:standards*; D003430:Cross-Sectional Studies; D005260:Female; D006336:Heart Massage / Q000592:standards*; D006801:Humans; D008297:Male; D008348:Manikins; D053580:Muscle Strength; D010809:Physical Fitness; D013334:Students; D014495:Universities; D055815:Young Adult