title: [Sports practice is related to parasympathetic activity in adolescents].
abstract: OBJECTIVE
  To analyze the relationship among sports practice, physical education class, habitual physical activity and cardiovascular risk in adolescents.
  
  
  METHODS
  Cross-sectional study with 120 schoolchildren (mean: 11.7±0.7 years old), with no regular use of medicines. Sports practice and physical education classes were assessed through face-to-face interview, while habitual physical activity was assessed by pedometers. Body weight, height and height-cephalic trunk were used to estimate maturation. The following variables were measured: body fatness, blood pressure, resting heart rate, blood flow velocity, intima-media thickness (carotid and femoral) and heart rate variability (mean between consecutive heartbeats and statistical index in the time domain that show the autonomic parasympathetic nervous system activity root-mean by the square of differences between adjacent normal R-R intervals in a time interval. Statistical treatment used Spearman correlation adjusted by sex, ethnicity, age, body fatness and maturation.
  
  
  RESULTS
  Independently of potential confounders, sports practice was positively related to autonomic parasympathetic nervous system activity (β=0.039 [0.01; 0.76]). On the other hand, the relationship between sport practice and mean between consecutive heartbeats (β=0,031 [-0.01; 0.07]) was significantly mediated by biological maturation.
  
  
  CONCLUSIONS
  Sport practice was related to higher heart rate variability at rest.
authors.affiliation: Universidade Estadual Paulista (Unesp), Rio Claro, SP, Brasil. Electronic address: suziungari@yahoo.com.br.
authors.forename: Suziane Ungari
authors.initials: SU
authors.lastname: Cayres
authors.affiliation: Universidade Estadual Paulista (Unesp), Presidente Prudente, SP, Brasil.
authors.forename: Luiz Carlos Marques
authors.initials: LC
authors.lastname: Vanderlei
authors.affiliation: Faculdade de Ciências do Desporto e Educação Física, Universidade de Coimbra, Coimbra, Portugal.
authors.forename: Aristides Machado
authors.initials: AM
authors.lastname: Rodrigues
authors.affiliation: Faculdade de Ciências do Desporto e Educação Física, Universidade de Coimbra, Coimbra, Portugal.
authors.forename: Manuel João Coelho E
authors.initials: MJ
authors.lastname: Silva
authors.affiliation: Universidade Estadual Paulista (Unesp), Rio Claro, SP, Brasil.
authors.forename: Jamile Sanches
authors.initials: JS
authors.lastname: Codogno
authors.affiliation: Universidade Federal de São Paulo (Unifesp), São Paulo, SP, Brasil.
authors.forename: Maurício Fregonesi
authors.initials: MF
authors.lastname: Barbosa
authors.affiliation: Universidade Estadual Paulista (Unesp), Rio Claro, SP, Brasil.
authors.forename: Rômulo Araújo
authors.initials: RA
authors.lastname: Fernandes
mesh_terms: D000293:Adolescent; D002320:Cardiovascular Physiological Phenomena; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D010275:Parasympathetic Nervous System / Q000502:physiology*; D013177:Sports / Q000502:physiology*
keywords: Adolescent; Adolescente; Autonomic nervous system; Carotid intima‐media thickness; Espessura mediointimal carotídea; Frequência cardíaca; Heart rate; Prática esportiva; Sistema nervoso autônomo; Sports practice