title: The impact of exercise intensity on the release of cardiac biomarkers in marathon runners.
abstract: We sought to determine the influence of exercise intensity on the release of cardiac troponin I (cTnI) and N-terminal pro-brain natriuretic peptide (NT-proBNP) in amateur marathon runners. Fourteen runners completed three exercise trials of the same duration but at exercise intensities corresponding to: (a) a competitive marathon [mean ± SD: heart rate 159 ± 7 beat min(-1), finish time 202 ± 14 min]; (b) 95% of individual anaerobic threshold [heart rate 144 ± 6 beat min(-1)] and; (c) 85% of individual anaerobic threshold [heart rate 129 ± 5 beat min(-1)]. cTnI and NT-proBNP were assayed from blood samples collected before, 30 min and 3 h post-exercise for each trial. cTnI and NT-proBNP were not different at baseline before each trial. After exercise at 85% of individual anaerobic threshold cTnI was not significantly elevated. Conversely, cTnI was elevated after exercise at 95% of individual anaerobic threshold (0.016 μg L(-1)) and to an even greater extent after exercise at competition intensity (0.054 μg L(-1)). Peak post-exercise values of NT-proBNP were elevated to a similar extent after all exercise trials (P < 0.05). The upper reference limit for cTnI (0.04 μg L(-1)) was exceeded in six subjects at competition intensity. No data for NT-proBNP surpassed its upper reference limit. Peak post-exercise values for cTnI and NT-proBNP were correlated with their respective baseline values. These data suggest exercise intensity influences the release of cTnI, but not NT-proBNP, and that competitive marathon running intensity is required for cTnI to be elevated over its upper reference limit.
authors: Section of Physical Educations and Sports, University of Zaragoza, Saragossa, Spain.
authors: Alejandro
authors: A
authors: Legaz-Arrese
authors: Keith
authors: K
authors: George
authors: Luis Enrique
authors: LE
authors: Carranza-García
authors: Diego
authors: D
authors: Munguía-Izquierdo
authors: Teresa
authors: T
authors: Moros-García
authors: Enrique
authors: E
authors: Serrano-Ostáriz
mesh_terms: D000328:Adult; D054874:Athletic Performance / Q000502:physiology; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods; D006321:Heart / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D009206:Myocardium / Q000378:metabolism; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D010807:Physical Endurance / Q000502:physiology; D012420:Running / Q000502:physiology*; D019210:Troponin I / Q000097:blood*
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; D019210:Troponin I; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain