title: Influence of 12 weeks of jogging on magnetic resonance-determined left ventricular characteristics in previously sedentary subjects free of cardiovascular disease.
abstract: Hypertrophy of the left ventricle is a diagnostic dilemma in subjects who engage in regular endurance exercise. We studied prospectively whether endurance training in previously sedentary young and middle-aged men and women can alter left ventricular (LV) characteristics. We recruited 33 healthy young and middle-aged subjects (18 women, 15 men, ages 21 to 59 years) to undergo 12 weeks of home-based brisk walking and jogging at a target heart rate > or =120 beats/min for > or =30 minutes 3 times a week. LV characteristics were measured by cine magnetic resonance imaging. Training intensity as estimated by heart rate correlated positively with the increase in LV myocardial area (r = 0.51, p = 0.005) in the 28 men and women completing the study. In the 13 men and women who trained with heart rate of > or =120 beats/min, LV myocardial area was larger after than before training (17.7 +/- 2.9 vs 16.8 +/- 2.8 cm(2), p <0.05). Moreover, in these subjects LV myocardial area increased more (5.5 +/- 9.0% vs -3.0 +/- 5.0%) than in the 15 men and women who trained at a lower intensity (p <0.05). LV end-systolic and end-diastolic area and ejection fraction did not change significantly. In conclusion, moderate-to-vigorous endurance training at moderate volumes does not influence LV end-diastolic volume or ejection fraction, but has a minor influence on LV hypertrophy in previously sedentary young and middle-aged men and women.
authors.affiliation: Department of Clinical Radiology, Kuopio University, Kuopio University Hospital, Finland. petri.sipola@kuh.fi
authors.forename: Petri
authors.initials: P
authors.lastname: Sipola
authors.forename: Jari
authors.initials: J
authors.lastname: Heikkinen
authors.forename: David E
authors.initials: DE
authors.lastname: Laaksonen
authors.forename: Raimo
authors.initials: R
authors.lastname: Kettunen
mesh_terms: D000328:Adult; D005260:Female; D006339:Heart Rate; D006352:Heart Ventricles / Q000254:growth & development*; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000175:diagnosis*; D007590:Jogging / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010807:Physical Endurance; D013997:Time Factors; D016277:Ventricular Function, Left