title: Heart rate variability, blood pressure variability, and baroreflex sensitivity in overtrained athletes.
abstract: OBJECTIVE
  To assess the effects of abruptly intensified physical training on cardiovascular control.
  
  
  METHODS
  Retrospective longitudinal study.
  
  
  METHODS
  Research laboratory.
  
  
  METHODS
  Ten healthy athletes (5 men and 5 women) from track and field as well as triathlon.
  
  
  METHODS
  A 2-week training camp, including daily stepwise increasing cycling tests, running of 40 minutes, and additional cycling of 60 minutes.
  
  
  METHODS
  Time and frequency domain parameters of resting heart rate and blood pressure variability (HRV and BPV) and baroreflex sensitivity (BRS), before, during, and after the training camp.
  
  
  RESULTS
  We found significantly reduced HRV during the training camp (mean beat-to-beat interval: 1042 [937 to 1194] ms vs. 933 [832 to 1103] ms vs. 1055 [947 to 1183] ms, P < 0.01; root-mean-square of beat-to-beat interval differences: 68 [52 to 95] ms vs. 52 [38 to 71] ms vs. 61 [48 to 78] ms, P < 0.05). Further, BRS was significantly reduced: 25.2 (20.4 to 40.4) ms/mmHg vs. 17.0 (12.9 to 25.7) ms/mmHg vs. 25.7 (18.8 to 29.1) ms/mmHg, P < 0.05. These effects disappeared at a large degree after 3 to 4 days of recovery.
  
  
  CONCLUSIONS
  Abruptly intensified physical training results in an altered autonomic cardiovascular activity towards parasympathetic inhibition and sympathetic activation that can be monitored by means of HRV and BRS analyses and might provide useful markers to avoid the overtraining syndrome.
authors.affiliation: Department of Medical Engineering, University of Applied Sciences Jena, Germany. mbaumert@eleceng.adelaide.edu.au
authors.forename: Mathias
authors.initials: M
authors.lastname: Baumert
authors.forename: Lars
authors.initials: L
authors.lastname: Brechtel
authors.forename: Jürgen
authors.initials: J
authors.lastname: Lock
authors.forename: Mario
authors.initials: M
authors.lastname: Hermsdorf
authors.forename: Roland
authors.initials: R
authors.lastname: Wolff
authors.forename: Vico
authors.initials: V
authors.lastname: Baier
authors.forename: Andreas
authors.initials: A
authors.lastname: Voss
mesh_terms: D000328:Adult; D001265:Athletic Injuries / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D001794:Blood Pressure / Q000502:physiology*; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006306:Health Surveys; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D010806:Physical Education and Training; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D014142:Track and Field / Q000193:education*