Background: Anthropometric characteristics, lifestyle, and baseline biological markers of Japanese non-professional ultra-marathon runners have not been fully assessed.
Methods: We evaluated anthropometric characteristics, lifestyle, and baseline biological markers of 180 Japanese amateur ultra-marathon runners (144 males [mean age: 50.5 +/- 9.4 (standard deviation) years] and 36 females [48.9 +/- 6.9]), and compared them with those of participants in a community heath check-up program and with the figures in the literature. We furthermore evaluated baseline blood indices according to monthly running distance with analysis of variance adjusted for age, body mass index, smoking and alcohol drinking habits.
Results: The ultra-marathon runners demonstrated more favorable values for body mass index and bone density, and the proportion of smoking, and undertaking physical activity (for both sexes), eating breakfast (for males), and having daily bowel movements (for females), while greater proportion of alcohol drinking habit (for both sexes), than the comparison group. Average monthly running distances and standard deviations (km) were 257.2 +/- 128.9 for males and 209.0 +/- 86.2 for females. Male runners possessed beneficial markers, including lowered triglyceride and elevated high-density lipoprotein cholesterol, and their values showed hockey-stick (or inverse hockey-stick) patterns depending on their monthly running distance. Some subjects running more than 300 km/month exhibited signs of an over-reaching/training syndrome, including somewhat lowered hemoglobin, ferritin and white blood cell count, and elevated creatine kinase and lactate dehydrogenase.
Conclusions: Together with a desirable lifestyle, Japanese non-professional ultra-marathon runners with vigorous exercise habit demonstrated a preferable health status according to biological indices.