[Effects of long-term endurance training on left ventricular dimensions and function in female distance runners]

Ultrasoundcardiogram (UCG) was measured to evaluate the effects of 2 years of endurance training on left ventricular dimensions and function in 3 female collegiate runners (mean age 19.7 years). All subjects had had an experience in endurance training as athletes and underwent the endurance training at the college for two years. Training consisted mainly of about 2 hours of running, 3 to 4 days a week. Training effects were found as measured by a 5000m-run pretraining (mean 19: 40.3 min) and post-training (mean 18: 49.3 min). The average increase in maximal oxygen uptake (VO2max/kg) after training was 9.4% (P < 0.05). UCG's dimensional variables such as LVDd, LVPWT and IVST in the post-training period did not reveal any increase. However, LVDs as a cardiac dimension showed a tendency to decrease, and functional variables such as SV, EF, FS showed a tendency to increase. This functional improvement appeared to be due to a decrease in LVDs. From these results, it is likely that the endurance training prior to this study might have helped an effective adaptation in their cardiac dimensions. Thus, we suggest that prior to this study cardiac dimensions had extended and enlarged to a certain extent, and then cardiac function might be improved as the subsequent physiological phenomenon.