title: Acute effect of intermittent and continuous aerobic exercise on release of cardiac troponin T in sedentary men.
abstract: BACKGROUND
  Studies have shown that acute exercise can increase serum concentrations of cardiac biomarkers, including cardiac troponin T (cTnT). We investigated the acute effects of intermittent (IE) and continuous (CE) exercise at the same cardiac workload on myocardial necrosis biomarkers in sedentary men.
  
  
  METHODS
  Eleven sedentary healthy men aged 22.3±1.9years completed the study. The subjects were divided into two groups and performed, in random order, IE (intensity alternating between 50% (2min) and 80% (1min) HRreserve) or CE (60% HRreserve). The study was designed as a single-blinded randomised crossover trial performed on two distinct experimental days separated by a 1-week washout period. Each session consisted of 40min of aerobic exercise, either IE or CE, on a treadmill. Blood samples were taken before (PRE), immediately after (POST) and 1h after (POST-1) each exercise session.
  
  
  RESULTS
  hs-cTnT significantly increased immediately after exercise in both protocols and remained elevated at POST-1 (P<0.05). There was no significant difference between POST and POST-1 values(P>0.05). Neither CE nor IE caused any significant change in CK-MB (P>0.05). The results also showed that HR and RPP increased significantly following both exercise protocols (P=0.001).
  
  
  CONCLUSIONS
  In summary, both CE and IE results in increased serum concentrations of hs-cTnT in sedentary men. However, this increase does not seem to be caused by the irreversible death of cardiomyocytes. CE resulted in a greater hs-cTnT concentration than IE.
authors.affiliation: Department of Exercise Physiology, Faculty of Physical Education and Sport Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
authors.forename: Rouhollah
authors.initials: R
authors.lastname: Ranjbar
authors.affiliation: Department of Exercise Physiology, Faculty of Physical Education and Sport Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran. Electronic address: ahmadi_ma@yahoo.com.
authors.forename: Mohammad Amin
authors.initials: MA
authors.lastname: Ahmadi
authors.affiliation: Department of Sport Science, Jahrom University, Jahrom, Iran.
authors.forename: Abdossaleh
authors.initials: A
authors.lastname: Zar
authors.affiliation: College of Life and Environmental Sciences, St Luke's Campus, University of Exeter, Exeter, UK; Department of Nutrition, Exercise and Sports, The August Krogh Building, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Krustrup
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D015444:Exercise / Q000502:physiology*; D006801:Humans; D008297:Male; D057185:Sedentary Behavior; D013997:Time Factors; D016896:Treatment Outcome; D020107:Troponin T / Q000097:blood*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D020107:Troponin T
keywords: CK-MB; Cardiac troponin T; Continuous exercise; Intermittent exercise