Left ventricular chamber size predicts the race time of Japanese participants in a 100 km ultramarathon

OBJECTIVE: As a subanalysis of an echocardiographic study performed on 291 Japanese participants in a 100 km ultramarathon, to estimate predictors of race time. METHODS: A total of 247 male participants in a 100 km ultramarathon (age 20-73 years) were examined by echocardiography. Correlations between age, body surface area, monthly running distance, or echocardiographic variables and the race time were examined. RESULTS: According to simple regression analysis, age (r = 0.299, p < 0.0001), monthly running distance (r = -0.388, p < 0.0001), left ventricular end diastolic diameter (r = -0.300, p < 0.0001), and left ventricular end systolic diameter (r = -0.325, p < 0.0001) correlated significantly with the race time. When multiple regression analysis was performed, age (f = 2.364), monthly running distance (f = -0.113), and left ventricular end systolic diameter (f = -2.361) remained significant predictors of the race time. CONCLUSION: Left ventricular diameter predicts the race time for a 100 km ultramarathon, in addition to age and amount of training.