Ending a race early is a difficult reality for many racers. Months of training and expectations usually lead to a goal of finishing a race. But a lot can happen out there. In the video below, a team ends their race earlier than expected due to an ill teammate. The tone and body language of the athletes communicates their disappointment.
The racer was feeling ill and "lost his food." Nausea during an endurance event is not uncommon, even for the best trained athlete. First, the lead up to the race is often stressful--packing, traveling, checking in, gear sorting, pre-race briefings, sleeplessness. The last 24 hours before a race might be some of the most important for bodily nutrition. Experts who often spurn supplements praise their use before a race to ensure levels are "topped off."
Racing stresses the body, including the GI tract. While exercising, oxygen-rich blood is diverted away from the abdomen to the muscles working to sustain the movement. Ingesting too much food, even by trying to stay on pace with calorie intake, can cause issues because your stomach doesn't have the necessary nutrients to break down the food.
Intense exercise also increases the pressure on in the intra-abdominal space putting pressure on the stomach. Using the core muscles and taking heavier breaths can force the stomach contents back up.
Often, adventure racers will "practice" eating during training sessions. It's important to have the mind and body experience that aspect of extended exercise and determine strategies to combat issues when they arise.
Hydration levels are another issue that can lead to nausea. Dehydration from not consuming enough water to replace that which is sweated out or used internally can lead to nausea and vomiting. A person's body needs water to break down food. To conserve the water remaining in the system, a body will eject stomach contents. Vomiting while dehydrated leads to a downward spiral as the body will become more dehydrated.
However, too much water can also be a problem as the sodium levels will be off. Hyponatraemia is an electrolyte imbalance, a condition that gatorade was developed to help combat. Racers will often carry "e-taps" or electrolyte pills to make sure they ingest enough sodium.
There is no way of knowing exactly why the athlete in the video "lost his food." Perhaps if he rested and sipped water instead of paddling the last section he might have recovered. Or there might not have been anything he or the team could have done. Regardless, an early tap out is never fun.