title: Physical activity and aerobic fitness are positively associated with heart rate variability in obese adults.
abstract: BACKGROUND
  Autonomic nervous system (ANS) dysfunction and obesity are intrinsically related to each other. In normal-weight subjects physical activity (PA) and fitness are related to cardiovascular autonomic regulation, providing evidence that aerobic training may improve ANS functioning measured by heart rate variability (HRV). The goal of this study was to investigate the association between lifetime PA, aerobic fitness and HRV in obese adults.
  
  
  METHODS
  Participants included 107 (87 females) volunteers (mean age 44.5 years, median BMI 35.7) who completed health and lifestyle questionnaires and measurements of maximal aerobic performance, anthropometry and 24 h HRV.
  
  
  RESULTS
  In the multivariate linear regression analyses, lifetime physical activity explained 40% of the variance in normal R-R intervals (SDNN). Each 1-category increase in the activity index increased SDNN by 15.4 (P = .009) and 24% of the variance in natural logarithmic value of ultra-low frequency power (P = .050). High measured VO2max explained 45% of the variance in natural logarithmic value of high-frequency power (P = .009) and 25% of the variance in low frequency/high frequency ratio (P < .001).
  
  
  CONCLUSIONS
  Lifetime physical activity and aerobic fitness may reduce obesity-related health risks by improving the cardiac autonomic function measured by HRV in obese working-age subjects. This research supports the role of lifetime physical activity in weight management strategies and interventions to reduce obesity-related health risks.
authors: Dept of Sports and Exercise Medicine, Oulu Deaconess Institute, Oulu, Finland.
authors: Kaisu Marjut
authors: KM
authors: Kaikkonen
authors: Raija Irmeli
authors: RI
authors: Korpelainen
authors: Mikko P
authors: MP
authors: Tulppo
authors: Hannu Sakari
authors: HS
authors: Kaikkonen
authors: Marja Liisa
authors: ML
authors: Vanhala
authors: Mika Antero
authors: MA
authors: Kallio
authors: Sirkka M
authors: SM
authors: Keinänen-Kiukaanniemi
authors: Juha Tapani
authors: JT
authors: Korpelainen
mesh_terms: D000328:Adult; D000368:Aged; D000886:Anthropometry; D001341:Autonomic Nervous System; D002319:Cardiovascular System; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000503:physiopathology*; D010101:Oxygen Consumption / Q000502:physiology; D010809:Physical Fitness / Q000502:physiology*; D011795:Surveys and Questionnaires