Concentric myocardial hypertrophy after one year of increased training volume in experienced distance runners.
OBJECTIVE
As evidence on the predominant type of cardiac hypertrophy due to endurance running training is inconsistent, the aim of this study was to investigate the effect of increased training volume on echocardiographic variables of distance runners.


METHODS
Twenty three adult, experienced, male distance runners underwent standard two dimensionally guided M mode and Doppler echocardiography before and after a one year period during which they were randomly allocated to either control (n = 11) or intervention (n = 12) groups. The intervention group increased their training volume from (mean (SD)) 8.0 (3.0) to 12.5 (3.9) hours/week without increasing the intensity, and the controls changed neither training parameter.


RESULTS
In the intervention group, training induced an increase in left ventricular (LV) mass (from 240.4 (53.8) to 279.5 (60.6) g, p<0.001) and LV mass index (from 126.7 (28.2) to 147.6 (32.3) g/m2, p<0.001) mainly due to an increase in end diastolic interventricular septum (from 10.4 (1.8) to 11.5 (1.7) mm, p<0.01) and LV posterior wall thickness (from 10.4 (1.6) to 11.5 (1.6) mm, p<0.001). No significant changes in LV internal diameter or measured indices of LV function occurred (p>0.05). The sum of the right ventricular diameter and wall thickness was greater after the increased volume training (p<0.05). None of the variables changed significantly in the control group (p>0.05).


CONCLUSIONS
In experienced, subelite distance runners, further increasing the training volume results in concentric cardiac hypertrophy.
Venckunas
T
T
Department of Applied Physiology and Health Education, Lithuanian Academy of Physical Education, Sporto 6, 44221-Kaunas, Lithuania. t.venckunas@lkka.lt
Stasiulis
A
A
Raugaliene
R
R
D000293:Adolescent; D000328:Adult; D006332:Cardiomegaly / Q000000981:diagnostic imaging / Q000209:etiology*; D005080:Exercise Test / Q000379:methods; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging / Q000209:etiology; D019344:Lactic Acid / Q000097:blood; D008137:Longitudinal Studies; D008297:Male; D010807:Physical Endurance / Q000502:physiology*; D012420:Running / Q000502:physiology*; D014463:Ultrasonography
D019344:Lactic Acid