Nausea is associated with endotoxemia during a 161-km ultramarathon. During an ultramarathon, many runners suffer from digestive problems such as nausea. An American group examined possible relationships between digestive problems and various laboratory parameters. Amazingly, it was found that parameters of endotoxemia (= poisoning caused by the decay of bacteria are associated with digestive problems with digestion problems with the release of endotoxins. This new aspect can be found under https://pubmed.ncbi.nlm.nih.gov/26707127/