Table 4.

Prevalence of exercise-associated hyponatremia (EAH) in ultra-marathons.

Ultramarathon	Distance	Prevalence
Below 100 km
Six Foot Track Marathon, New South Wales, Australia [145]	45 km trail	0% in 9 subjects out of 775 starters
Two Oceans 56-km ultra-marathon, Cape Town, South Africa [146]	56 km	0%
Cradle Mountain Run, Tasmania, Australia [147]	85 km	2% of 41 subjects
100 km
100 km Lauf Biel, Switzerland [132]	100 km	0% of 50 men
100 km Lauf Biel, Switzerland [148]	100 km	0% of 11 women
100 km Lauf Biel, Switzerland [149]	100 km	4.8% of 145 subjects
100 km Lauf Biel, Switzerland [150]	100 km	5% in 19 women and 11 % in 24 men
100 km Lauf Biel, Switzerland [126]	100 km	5% of 95 men
100 miles
Western States Endurance Run, California, USA [151]	100 miles	5.8% of 207 subjects
Western States Endurance Run, California, USA [152]	100 miles	6% of 207 subjects
Western States Endurance Run, California, USA [83]	100 miles	6.6% of 157 subjects
Western States Endurance Run, California, USA [57]	100 miles	15.1% of 669 subjects
Western States Endurance Run, California, USA [153]	100 miles	16% of 373 subjects
The Great North Walk 100s, New South Wales, Australia [55]	100 miles	26.7 % in 4 of 15 subjects
Western States Endurance Run, California, USA [56]	100 miles	30% of 47 subjects
Western States Endurance Run, California, USA [130]	100 miles	30% of 47 subjects
Rio Del Lago 100-Mile Endurance Run Granite Bay, California, USA [154]	100 miles	51.2%