title: Effect of exercise training and detraining in autonomic modulation and cardiorespiratory fitness in breast cancer survivors.
abstract: BACKGROUND
  Breast cancer is one of the leading causes of death worldwide. Heart rate variability (HRV) has attracted scientific community attention in different pathologies, becoming thus an ultimate importance tool in both clinical and research setting, being a good predictor of cardiac events and mortality risk and also used in physical exercise and sports in general. The aim of the present study was to evaluate 12 weeks of exercise training and six weeks of detraining in cardiorespiratory capacity, and autonomic modulation in breast cancer patients.
  
  
  METHODS
  The sample was composed of 18 females (9 controls and 9 exercised), (aged 30-60 years). The HRV in the time and frequency domain was performed using an electrocardiogram before, after 12 weeks of the session of exercise training and after six weeks of detraining. Shapiro-Wilk and Mann-Whitney tests were made.
  
  
  RESULTS
  No significant changes in time domain were found. In the frequency domain, 12 weeks of exercise training promote a decrease in LF (nu) and decrease in HF (nu) Index. The exercise training period promoted a decrease in LF/HF. The autonomic data returned to baseline levels after the detraining period. However, cardiorespiratory capacity remained increased after the detraining period.
  
  
  CONCLUSIONS
  These data demonstrated that exercise training can be used to prevent autonomic dysfunction in breast cancer patients, but detraining promotes loss of all autonomic benefits.
authors.affiliation: Department of Physical Education, Federal University of Maranhão, São Luís, Brazil.
authors.forename: Andréa
authors.initials: A
authors.lastname: Dias Reis
authors.affiliation: Department of Physical Education, Federal University of Maranhão, São Luís, Brazil.
authors.forename: João B
authors.initials: JB
authors.lastname: Silva Garcia
authors.affiliation: Department of Physical Education, Federal University of Maranhão, São Luís, Brazil.
authors.forename: Renata
authors.initials: R
authors.lastname: Rodrigues Diniz
authors.affiliation: Department of Physical Education, Federal University of Maranhão, São Luís, Brazil.|LACORE, Laboratory of Cardiovascular Adaptations to Exercise, Federal University of Maranhão, São Luís, Maranhão, Brazil.
authors.forename: Antonio C
authors.initials: AC
authors.lastname: Silva-Filho
authors.affiliation: Department of Physical Education, Federal University of Maranhão, São Luís, Brazil.|LACORE, Laboratory of Cardiovascular Adaptations to Exercise, Federal University of Maranhão, São Luís, Maranhão, Brazil.
authors.forename: Carlos J
authors.initials: CJ
authors.lastname: Dias
authors.affiliation: Department of Physical Education, Federal University of Maranhão, São Luís, Brazil.|Department of Physical Education and Sport, University of Espírito Santo, Vitória, Brazil.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Leite
authors.affiliation: Department of Physical Education, Federal University of Maranhão, São Luís, Brazil - cristiano.mostarda@gmail.com.|LACORE, Laboratory of Cardiovascular Adaptations to Exercise, Federal University of Maranhão, São Luís, Maranhão, Brazil.
authors.forename: Cristiano
authors.initials: C
authors.lastname: Mostarda
mesh_terms: D000328:Adult; D001341:Autonomic Nervous System / Q000502:physiology*; D001943:Breast Neoplasms / Q000503:physiopathology* / Q000628:therapy; D000073116:Cancer Survivors / Q000706:statistics & numerical data; D018270:Carcinoma, Ductal, Breast / Q000503:physiopathology* / Q000628:therapy; D000072599:Cardiorespiratory Fitness / Q000502:physiology*; D018493:Cardiovascular Deconditioning / Q000502:physiology; D016022:Case-Control Studies; D004562:Electrocardiography; D015444:Exercise / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D013997:Time Factors