title: A comparison of the physiological demands imposed by competing in a half-marathon vs. a marathon.
abstract: BACKGROUND
  While there is widespread scientific information about the physiological challenges imposed on elite endurance runners during competitions, the information regarding the amateur population is scarce. The aim of this study was to compare the physical and physiological load imposed by competing in a real half-marathon vs. a marathon race.
  
  
  METHODS
  From a larger group of participants, we selected 22 experienced runners who were matched in pairs (11 marathoners and 11 half-marathoners) for age and anthropometric data. Participants completed their respective distances on the same day and circuit while race time was measured by means of chip timing. Sweat samples were obtained during the race using sweat patches. Before and after the race, a sample of venous blood was obtained and jump height was measured during a countermovement jump. Participants also rated their perception of leg muscle pain at the end of the race.
  
  
  RESULTS
  Running pace was similar for half-marathoners vs. marathoners (3.3±0.4 vs. 3.1±0.4 m·s-1; P=0.36). At the end of the race, jump height reduction (-11±12% vs. -25±19%; P=0.03), serum myoglobin concentration (186.1±93.6 vs. 564.1±370.7 µg·mL-1; P<0.01) and self-reported muscle pain (3.0 ±2.3 vs. 5.5 ±1.0 A.U.; P<0.01) were lower in half-marathoners vs. marathoners. Sweat rate (~1.0±0.3 L·h-1; P=0.79) and sweat sodium concentration (47.8±29.4 and 39.3±24.1 mmol·L-1; P=0.47) were similar for both groups but body mass reduction (-1.9±0.8% vs. -3.3±0.8%; P<0.01) and electrolyte imbalance were higher in marathoners.
  
  
  CONCLUSIONS
  Completing a marathon induces higher muscle fatigue, greater muscle fiber damage and perceived muscle pain levels and higher body water and electrolyte deficits than finishing a half-marathon with a similar running speed. This information could be valuable to improve physical training for endurance running disciplines.
authors.affiliation: Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain - jdelcoso@ucjc.edu.
authors.forename: Juan
authors.initials: J
authors.lastname: Del Coso
authors.affiliation: Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain.
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Salinero
authors.affiliation: Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Lara
authors.affiliation: Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain.|Performance and Sport Rehabilitation Laboratory, Castilla La Mancha University, Toledo, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Abián-Vicén
authors.affiliation: Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain.
authors.forename: César
authors.initials: C
authors.lastname: Gallo-Salazar
authors.affiliation: Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Areces
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000503:physiopathology*; D063806:Myalgia / Q000175:diagnosis; D009211:Myoglobin / Q000097:blood; D010807:Physical Endurance / Q000502:physiology*; D012420:Running / Q000502:physiology*; D013546:Sweating / Q000502:physiology; D014882:Water-Electrolyte Balance / Q000502:physiology; D055815:Young Adult
chemical_list: D015415:Biomarkers; D009211:Myoglobin