title: On site assessment of cardiac function and neural regulation in amateur half marathon runners.
abstract: Strenuous exercise variably modifies cardiovascular function. Only few data are available on intermediate levels of effort. We therefore planned a study in order to address the hypothesis that a half marathon distance would result in transient changes of cardiac mechanics, neural regulation and biochemical profile suggestive of a complex, integrated adaptation.
  
  
  
  We enrolled 35 amateur athletes (42±7 years). Supine and standing heart rate variability and a complete echocardiographic evaluation were assessed on site after the completion of a half marathon (postrace) and about 1 month after (baseline). Biochemical tests were also measured postrace.
  
  
  
  Compared to baseline, the postrace left ventricular end-diastolic volume was smaller, peak velocity of E wave was lower, peak velocity of A wave higher, and accordingly the E/A ratio lower. The postrace heart and respiratory rate were higher and variance of RR interval lower, together with a clear shift towards a sympathetic predominance in supine position and a preserved response to orthostasis. At baseline, athletes were characterised by a lower, although still predominant, sympathetic drive with a preserved physiological response to standing.
  
  
  
  Immediately after a half marathon there are clear marks that an elevated sympathetic cardiac drive outlasts the performance, together with decreased left ventricular diastolic volumes and slight modifications of the left ventricular filling pattern without additional signs of diastolic dysfunction or indices of transient left or right ventricular systolic abnormalities. Furthermore, no biochemical indices of any permanent cardiac damage were found.
authors.affiliation: IRCCS Fondazione Salvatore Maugeri, Istituto Scientifico di Milano , Milan , Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Dalla Vecchia
authors.affiliation: IRCCS Fondazione Salvatore Maugeri, Istituto Scientifico di Montescano , Pavia , Italy.
authors.forename: Egidio
authors.initials: E
authors.lastname: Traversi
authors.affiliation: Department of Biomedical Sciences for Health , Galeazzi Orthopedic Institute, University of Milan , Milan , Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Porta
authors.affiliation: IRCCS Istituto Clinico Humanitas, Sezione Medicina dell'Esercizio e Sindromi Funzionali, Rozzano , Milan , Italy ; Centro di ricerca Terapia Neurovegetativa e Medicina dell'esercizio, University of Milan, U.O. Telemedicina e Medicina dello Sport, Ospedale 'Luigi Sacco' , Milano , Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Lucini
authors.affiliation: Centro di ricerca Terapia Neurovegetativa e Medicina dell'esercizio, University of Milan, U.O. Telemedicina e Medicina dello Sport, Ospedale 'Luigi Sacco' , Milano , Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Pagani