Most triathletes that I know and have worked with have suffered from race day GI (gastro-intestinal) issues at some stage. These problems seem to affect athletes in longer distance events, sometimes 70.3 and definitely iron distance. The reasons for this are related to an inability to process the fluids and nutrients caused by:
- the quantity of concentrated sugary substances in the stomach
- lack of blood flow to the stomach
- too much fibre
Fortunately, it is possible to minimise each of the above and thus enjoy a more comfortable race. Firstly, with 36-48 hours to go before your race, reduce the consumption of fibre to a minimum and replace with plain white carbohydrates (white rice, pasta etc). Next, with 2 days to go, complete any carbohydrate loading by consuming 8-10g/kg of bodyweight and then on the day before the race, perform minimal training load and graze on similar white carbs. You will feel bloated initially but this will pass.
On race morning have a small breakfast 2-3 hours before race start time (approximately 50-60g of carbohydrates) and similar to what you normally have before a training day. Keep caffeine consumption to a minimum and stay hydrated in the minutes leading up to the start and during the event. Be mindful of the carbohydrates that you ingest. Fructose can cause GI problems for some athletes, so malto-dextrin could be a better alternative. Have a plan for the race – nutrition scientists recommend roughly 60g of carbs/hour of racing so work out how long you think you’ll be out there and how much nutrition you will need. Then calculate whether this will come from solids, gels or drinks. For longer races you may find that solids work better in the early part of the ride, and liquids closer to the run. Take in small amounts regularly rather than, say, eating a full energy bar in one go. Finally, use your chosen fuel in training and avoid anything new on race day.
Despite your best plans you may still find your stomach causing problems on race day. If this happens you can often work through this by slowing down a little and drinking small sips of water. The body has a remarkable ability to sort itself out given time.