The following is some advice I recently sent a newcomer to triathlon. She’s about to do her first Olympic distance race and has been recently having problems with hypoglycemia. I thought my advice might be useful to share here.
Please keep in mind that I am not a dietician. The following information is based on a lot of reading from many sources and my own experimentation on myself.
Here it is…
So, you want to shoot for 100 to 200 cal per hour. Have a decent breakfast (200 to 400 cal easily digested like a bagel with peanut butter and/or jam) about 2 to 3 hours before race start. Start fueling 10 to 15 min into the bike leg with a gel. If you’ve tried Gu and tolerate it well, stick to that. You want to shoot for 100 to 200 cal per hour up to 30 min left in your run. There’s no point in taking in anything else after that, it won’t hit your system in time to help you finish.
If it’s hot, you will need some additional electrolyte replacement, like Endurolytes.
Here’s an example of my typical race plan.
Oven roasted potatoes with butter, salt, pepper and parmesan for breakfast.
One gel within 20 min of starting if I’m feeling shaky or hungry.
Perpetuem and/or gels during the ride and run, 100 Cal every 45 min. If hot 2 to 3 Endurolyte capsules per hour.
Stop eating glucose based stuff after halfway point on the run (for an Oly). Keep taking in light electrolyte drink like Heed.
Keep in mind that your body can’t absorb sugars/carbohydrates without sodium present.
That would be plan A.
If my stomach gets bloated and feeling like things aren’t digesting then I decrease the amount of carb stuff (gels and perpetuem) I take in until it sorts itself out. This is a real possibility if you have not been maintaining your eating plan during training. So definitely may be a problem for you.
In general, it is better to eat on the light side than to over eat if you’re racing hard and uncertain of what you can tolerate. You’re much more likely to have stomach issues with hard efforts, especially in the heat. Once your stomach knots up, you won’t be able to digest fluids, even water, as well and the probability of dehydration and electrolyte imbalance is much worse. That’s a much more serious situation that hypoglycemia.
So be prepared to deviate from race plan A, either by lowering your effort so you can digest better and/or decreasing your caloric intake depending on how your body is handling it.
I hope that helps.