title: Rate of cardiac arrhythmias and silent brain lesions in experienced marathon runners: rationale, design and baseline data of the Berlin Beat of Running study.
abstract: BACKGROUND
  Regular exercise is beneficial for cardiovascular health but a recent meta-analysis indicated a relationship between extensive endurance sport and a higher risk of atrial fibrillation, an independent risk factor for stroke. However, data on the frequency of cardiac arrhythmias or (clinically silent) brain lesions during and after marathon running are missing.
  
  
  METHODS
  In the prospective observational "Berlin Beat of Running" study experienced endurance athletes underwent clinical examination (CE), 3 Tesla brain magnetic resonance imaging (MRI), carotid ultrasound imaging (CUI) and serial blood sampling (BS) within 2-3 days prior (CE, MRI, CUI, BS), directly after (CE, BS) and within 2 days after (CE, MRI, BS) the 38th BMW BERLIN-MARATHON 2011. All participants wore a portable electrocardiogram (ECG)-recorder throughout the 4 to 5 days baseline study period. Participants with pathological MRI findings after the marathon, troponin elevations or detected cardiac arrhythmias will be asked to undergo cardiac MRI to rule out structural abnormalities. A follow-up is scheduled after one year.
  
  
  RESULTS
  Here we report the baseline data of the enrolled 110 athletes aged 36-61 years. Their mean age was 48.8 ± 6.0 years, 24.5% were female, 8.2% had hypertension and 2.7% had hyperlipidaemia. Participants have attended a mean of 7.5 ± 6.6 marathon races within the last 5 years and a mean of 16 ± 36 marathon races in total. Their weekly running distance prior to the 38th BMW BERLIN-MARATHON was 65 ± 17 km. Finally, 108 (98.2%) Berlin Beat-Study participants successfully completed the 38th BMW BERLIN-MARATHON 2011.
  
  
  CONCLUSIONS
  Findings from the "Berlin Beats of Running" study will help to balance the benefits and risks of extensive endurance sport. ECG-recording during the marathon might contribute to identify athletes at risk for cardiovascular events. MRI results will give new insights into the link between physical stress and brain damage.
  
  
  BACKGROUND
  clinicaltrials.gov NCT01428778.
authors.affiliation: Department of Neurology, Charité Berlin Campus Benjamin Franklin, Hindenburgdamm 30, 12203, Berlin, Germany. georg.haeusler@charite.de
authors.forename: Karl Georg
authors.initials: KG
authors.lastname: Haeusler
authors.forename: Juliane
authors.initials: J
authors.lastname: Herm
authors.forename: Claudia
authors.initials: C
authors.lastname: Kunze
authors.forename: Matthias
authors.initials: M
authors.lastname: Krüll
authors.forename: Lars
authors.initials: L
authors.lastname: Brechtel
authors.forename: Jürgen
authors.initials: J
authors.lastname: Lock
authors.forename: Marc
authors.initials: M
authors.lastname: Hohenhaus
authors.forename: Peter U
authors.initials: PU
authors.lastname: Heuschmann
authors.forename: Jochen B
authors.initials: JB
authors.lastname: Fiebach
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Haverkamp
authors.forename: Matthias
authors.initials: M
authors.lastname: Endres
authors.forename: Gerhard Jan
authors.initials: GJ
authors.lastname: Jungehulsing
mesh_terms: D000328:Adult; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000453:epidemiology*; D058070:Asymptomatic Diseases; D015415:Biomarkers / Q000097:blood; D002544:Cerebral Infarction / Q000175:diagnosis / Q000453:epidemiology*; D015716:Electrocardiography, Ambulatory; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010807:Physical Endurance; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012107:Research Design; D018570:Risk Assessment; D012307:Risk Factors; D012420:Running; D013997:Time Factors; D014336:Troponin / Q000097:blood
chemical_list: D015415:Biomarkers; D014336:Troponin