title: Differential effects of variation in athletes training on myocardial morphophysiological adaptation in men: focus on ¹²³I-MIBG assessed myocardial sympathetic activity.
abstract: OBJECTIVE
  High intensity systematic physical training leads to myocardial morphophysiological adaptations. The goal of this study was to investigate if differences in training were correlated with differences in cardiac sympathetic activity.
  
  
  METHODS
  58 males (19-47 years), were divided into three groups: strength group (SG), (20 bodybuilders), endurance group (EG), (20 endurance athletes), and a control group (CG) comprising 18 healthy non-athletes. Cardiac sympathetic innervation was assessed by planar myocardial (123)I-metaiodobenzylguanidine scintigraphy using the early and late heart to mediastinal (H/M) ratio, and washout rate (WR).
  
  
  RESULTS
  Left ventricular mass index was significantly higher both in SG (P < .001) and EG (P = .001) compared to CG without a statistical significant difference between SG and EG (P = .417). The relative wall thickness was significantly higher in SG compared to CG (P < .001). Both left ventricular ejection fraction and the peak filling rate showed no significant difference between the groups. Resting heart rate was significantly lower in EG compared to CG (P = .006) and SG (P = .002). The late H/M ratio in CG was significantly higher compared to the late H/M for SG (P = .003) and EG (P = .004). However, WR showed no difference between the groups. There was no significant correlation between the parameters of myocardial sympathetic innervation and parameters of left ventricular function.
  
  
  CONCLUSIONS
  Strength training resulted in a significant increase in cardiac dimensions. Both strength and endurance training seem to cause a reduction in myocardial sympathetic drive. However, myocardial morphological and functional adaptations to training were not correlated with myocardial sympathetic activity.
authors.affiliation: Post Graduation Program in Research and Development - Medical Biotechnology, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil, douglas@pinheiromiranda.com.
authors.forename: Douglas Pinheiro
authors.initials: DP
authors.lastname: Miranda
authors.forename: Marcelo José
authors.initials: MJ
authors.lastname: dos Santos
authors.forename: Vera Maria Cury
authors.initials: VM
authors.lastname: Salemi
authors.forename: Edmundo Pereira Caparelli
authors.initials: EP
authors.lastname: de Oliveira
authors.forename: Hein J
authors.initials: HJ
authors.lastname: Verberne
authors.forename: Euclides Timóteo
authors.initials: ET
authors.lastname: da Rocha
mesh_terms: D019797:3-Iodobenzylguanidine; D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D006339:Heart Rate / Q000502:physiology*; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000294:innervation; D006801:Humans; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D055070:Resistance Training / Q000379:methods*; D012680:Sensitivity and Specificity; D013177:Sports / Q000502:physiology*; D013318:Stroke Volume / Q000502:physiology; D013564:Sympathetic Nervous System / Q000502:physiology*; D016277:Ventricular Function, Left / Q000502:physiology*; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine