Table 1 Baseline characteristics, responses to graded exercise testing (GXT), and ultra-marathon records. Data are in median (interquartile ranges). Characteristics All subjects (n=24) Age (years) 49.5 (47 - 54) Height (m) 168.3 (164.2 - 171.8) Weight (kg) 65.5 (64.2 - 71.4) BMI (kg·m-2) 23.7 (23.7 - 25.0) Marathon experience (month) 120.0 (78.8 - 141.8) Number of participated marathons 37.5 (20.0 - 60.8) Average completion time (min) 218 (202.75 - 230) Record time (min) (n =20) 198.0 (190.0 - 210.0) Graded exercise testing (GXT) Exercise intensity (RPE) 13 (11 - 13) VO2max (ml·kg-1·min-1) 47.0 (44.6 - 49.0) At rest HR (bpm) 60.0 (53.0 - 67.8) SBP (mmHg) 117 (108.0 - 128.0) DBP (mmHg) 77 (70.5 - 81.5) At maximum HR (bpm) 171.5 (164.5 - 181.5) SBP (mmHg) 215.0 (200.0 - 237.5) DBP (mmHg) 76.0 (68.0 - 82.8) Total completion time (min) 3614.5 (3393.0 - 3722.0) Mean speed (km/hr) 5.1 (5.0 - 5.5) From 0 to 100 km 7.6 (7.2 - 8.4) From 100 to 200 km 4.74 (4.6 - 5.1) * From 200 to 308 km 4.5 (4.3 - 4.6) *†  Treadmill graded exercise testing (GXT) was conducted 4 weeks prior to the ultramarathon race on all volunteers. The symbols next to the values indicate following meanings. * The difference is significant from 100 km, p < 0.001