Lifelong Physical Activity Regardless of Dose Is Not Associated With Myocardial Fibrosis

Circ Cardiovasc Imaging. 2016 Nov;9(11):e005511. doi: 10.1161/CIRCIMAGING.116.005511.

Abstract

Background: Recent reports have suggested that long-term, intensive physical training may be associated with adverse cardiovascular effects, including the development of myocardial fibrosis. However, the dose-response association of different levels of lifelong physical activity on myocardial fibrosis has not been evaluated.

Methods and results: Seniors free of major chronic illnesses were recruited from predefined populations based on the consistent documentation of stable physical activity over >25 years and were classified into 4 groups by the number of sessions/week of aerobic activities ≥30 minutes: sedentary (group 1), <2 sessions; casual (group 2), 2 to 3 sessions; committed (group 3), 4 to 5 sessions; and Masters athletes (group 4), 6 to 7 sessions plus regular competitions. All subjects underwent cardiopulmonary exercise testing and cardiac magnetic resonance imaging, including late gadolinium enhancement assessment of fibrosis. Ninety-two subjects (mean age 69 years, 27% women) were enrolled. No significant differences in age or sex were seen between groups. Median peak oxygen uptake was 25, 26, 32, and 40 mL/kg/min for groups 1, 2, 3, and 4, respectively. Cardiac magnetic resonance imaging demonstrated increasing left ventricular end-diastolic volumes, end-systolic volumes, stroke volumes, and masses with increasing doses of lifelong physical activity. One subject in group 2 had late gadolinium enhancement in a noncoronary distribution, and no subjects in groups 3 and 4 had evidence of late gadolinium enhancement.

Conclusions: A lifelong history of consistent physical activity, regardless of dose ranging from sedentary to competitive marathon running, was not associated with the development of focal myocardial fibrosis.

Keywords: athlete’s heart; exercise; magnetic resonance imaging; myocardial fibrosis.

Publication types

  • Comparative Study

MeSH terms

  • Age Factors
  • Aged
  • Cardiomegaly, Exercise-Induced*
  • Cardiomyopathies / diagnostic imaging
  • Cardiomyopathies / etiology*
  • Cardiomyopathies / pathology
  • Cardiorespiratory Fitness
  • Contrast Media / administration & dosage
  • Cross-Sectional Studies
  • Exercise Test
  • Exercise*
  • Female
  • Fibrosis
  • Humans
  • Magnetic Resonance Imaging, Cine
  • Male
  • Myocardium / pathology*
  • Oxygen Consumption
  • Predictive Value of Tests
  • Risk Factors
  • Time Factors
  • Ventricular Remodeling*

Substances

  • Contrast Media