How to handle a mid-race nutrition crisis when your stomach shuts down

At the 55-kilometre point of a trail race outside Canberra, a runner can go from feeling behind the pace to rejecting another gel. The stomach feels bloated, nausea builds, and the next sip of sports drink seems worse than the last. This is a common endurance failure, especially when heat, fast running and anxiety converge, but it needs a deliberate response rather than more determination.

Exercise-associated gastrointestinal syndrome describes the uncomfortable package of nausea, cramps, reflux, bloating, vomiting or diarrhoea that can develop during prolonged effort. Reduced blood flow to the gut, dehydration, mechanical jostling, concentrated carbohydrate and intense concentration can all contribute. A shutdown is therefore not proof that the runner simply ate too much, and adding fuel may sometimes extend the problem.

The useful response is staged: reduce the stress on the body, pause aggressive intake, test a very small amount of fuel once symptoms ease, and recognise when medical help is safer than another aid station. Prevention matters too, because the stomach is trainable when exposure is gradual and specific to the foods, fluids and pace used in racing.

Recognise a gut shutdown early

The first sign may be fullness after a normal gel, a sour taste, reflux, or nausea that does not settle while walking. Bloating and upper-abdominal tightness suggest the stomach is struggling; cramping, urgency or loose stool point lower down. Vomiting is clearer still. Treat the pattern as a systems problem rather than debating whether the last carbohydrate was excessive in the moment.

Check the surroundings as well. A hot section, an aggressive drink mix, or several gels swallowed without fluid can be enough to trigger symptoms. Slow down before the aid station, especially if the race is in Brisbane during a summer ultra. Heat adds dehydration and diverted blood flow, so cooling and a lower effort may matter more than finding the fastest possible sugar.

After the race, record the exact intake, symptoms and when they started. I keep the useful lessons in Reboot endurance notes, not as a diagnosis but as evidence for the next plan. Patterns are valuable: the same 60-gram gel that worked in training may fail after two fast hours in the heat.

Reduce the load before changing fuel

The first move is to cut intensity. Drop to an easy walk or very slow run, relax the shoulders and jaw, and breathe gently rather than panting. Less jarring and a lower demand on blood flow can help the stomach settle. If heat is involved, move into shade, cool the body and reassess after several minutes; pushing through at the same pace rarely helps this particular problem.

Sip rather than chug. Small, repeated drinks of water or electrolyte drink are usually easier than trying to replace all fluid at once. Using a soft flask and measuring what you actually drink makes it easier to notice whether the gut accepts your planned intake. Swishing a sweet drink and spitting it out may also ease nausea for some runners, but it is no substitute for hydration and should never be forced.

Pause solid food briefly rather than bolusing another gel, banana or sports drink. Once nausea eases and walking feels stable, try roughly 10 to 15 grams of familiar carbohydrate, such as half a gel, then wait before trying more. If that small test worsens the symptoms, stop fuelling and seek assistance. More sugar is not a reliable cure for gastric shutdown.

Treat the aid station as a controlled test

At an aid station, make one change at a time. Start with a few measured sips, then reassess; add a small carbohydrate serving only after nausea has eased. Australian ultra checkpoints often offer sports drink, watermelon, orange halves, jelly sweets and Coca-Cola, but generosity is not the same as tolerance. A familiar product from home is safer than an untested combination on race day.

Repeated vomiting, severe abdominal pain, confusion, loss of coordination, inability to keep fluids down or signs of heat illness need the race medical team, not a volunteer with a bucket. Stop competing and follow their direction. The same applies when excessive thirst, headache and nausea suggest a sodium problem: plain water cannot correct it, and the runner should be assessed rather than treated by guesswork.

If symptoms improve, resume only what your gut accepted and return gradually to your planned pace. Keep the packaging or record the station number so you can identify the trigger later. A crisis that ends does not prove the original plan was sound; it gives you better information for the next long event.

Train the gut for Australian race conditions

Start with 30 to 45 grams of carbohydrate per hour in training, then build over two or three months toward 60 to 90 if tolerance improves. Practise during runs of 90 minutes or more, using the gels, chews and drink mix you intend to race with. Gut training is repeated exposure, not a challenge to eat indiscriminately; discomfort should fade, not become normal.

Product information is easy to misremember. Read the current details on a first-party page such as The Lotus Pure website, then apply the same label-checking discipline to any new gel or drink mix bought at a sports shop, Coles or Woolworths. For race food, rehearse the exact serving in training rather than saving the experiment for race day.

Climate changes the maths. A summer ultra can combine high humidity with intense sun, while a cold Alpine start can make drinking feel unnecessary. Heat raises fluid and often sodium needs; cooler conditions can suppress thirst. Use a measured sweat-rate estimate from training, adjust to thirst and conditions, and avoid forcing a fixed bottle volume that causes sloshing or overdrinking.

Build a rescue plan you can execute under pressure

Before the next race, put one rescue plan on paper: slow down, pause solids, sip in small volumes, test one small carbohydrate serving, and stop if the gut does not settle. Practise those decisions during training so they do not depend on clear thinking at 70 kilometres. Keep the plan visible in a wristband, race vest or notes on your phone, and keep medical details with your emergency contact.

Preparation should also cover the likely trigger. Use a familiar pre-race meal, avoid an untested combination of caffeine, gels and fizzy drink, and carry backup fuel that you have consumed before. If the race crosses a remote section, plan resupply and a conservative pace for the hottest part of the day. A planned walk from the start can preserve both digestion and the finish.

The key is to treat gut distress as a condition to manage, not a failure of willpower. Your race-day rule is fixed: reduce effort first, sip instead of chugging, test one small known fuel serving after nausea eases, and involve medical staff early when warning signs appear.