title: Effects of exercise training on heart-rate-variability indices in individuals with Down Syndrome.
abstract: OBJECTIVE
  To investigate the effects of an exercise-training program on heart-rate-variability (HRV) indices in individuals with Down syndrome (DS).
  
  
  METHODS
  Controlled clinical trial.
  
  
  METHODS
  10 people with DS, age 24.2 +/- 5.1 y (group A), and 10 age-matched healthy sedentary individuals (group B).
  
  
  METHODS
  At baseline all subjects underwent a clinical examination and an ambulatory 24-h Holter monitoring for the evaluation of cardiac autonomic-nervous-system (ANS) activity by time- and frequency-domain analysis.
  
  
  METHODS
  After initial evaluation, group A followed a 6-mo exercise-training program and thereafter underwent the same HRV analysis.
  
  
  RESULTS
  At the beginning of the study, group A showed a higher LF:HF ratio than group B, indicating impaired sympathovagal balance, likely because of lesser vagal modulation. Moreover, both time- and frequency-domain indices in group A were significantly lower than in group B. At the end of the study, exercise training was found to improve the sympathovagal balance, mainly by increasing vagal activity, in group A.
  
  
  CONCLUSIONS
  The results indicate that individuals with DS have ANS dysfunction that can be improved by exercise's increasing the parasympathetic modulation.
authors.affiliation: Dept of Physical Education and Sports Science, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Fani
authors.initials: F
authors.lastname: Giagkoudaki
authors.forename: Eleftherios
authors.initials: E
authors.lastname: Dimitros
authors.forename: Evangelia
authors.initials: E
authors.lastname: Kouidi
authors.forename: Asterios
authors.initials: A
authors.lastname: Deligiannis
mesh_terms: D001341:Autonomic Nervous System / Q000503:physiopathology; D016022:Case-Control Studies; D004314:Down Syndrome / Q000503:physiopathology* / Q000628:therapy; D015716:Electrocardiography, Ambulatory; D005081:Exercise Therapy; D006339:Heart Rate; D006801:Humans; D057185:Sedentary Behavior; D018709:Statistics, Nonparametric; D013997:Time Factors; D055815:Young Adult