A recent study in the International Journal of Sports Medicine reported a 24-hour non-stop ultra-marathon 0-20 degrees Celsius resulted in a circulatory endotoxaemia and pro-inflammatory cytokinaemia, counteracted by a compensatory anti-inflammatory response. The findings are the results of blood samples from 17 runners before and after the ultra-marathon.
Here are three things to know:
1. Scientific American reported that the runners' "guts got leaky — due to a lack of blood flow to the intestines." This was an immune response in the athletes' bodies.
2. Blood samples were analyzed for gram-negative bacterial endotoxin, C-reactive protein, cytokine profile and plasma osmolality.
3. Gastrointestinal symptoms were reported by 75 percent of ultra-endurance runners, with no symptoms reported by the control group.