After months of hard training, every runner wants to perform their best on race day. There are a few culprits for a bad race – inclement weather, poor pacing – but few seem to strike as often as gastrointestinal distress. Whether it manifests as nausea, vomiting, mid-race bathroom stops, or cramping, research published in Human Kinetics Journals suggests that up to 90% of runners experience symptoms of GI distress on race day.
Severe GI distress can play out in one of two scenarios on race day:
Neither scenario is desirable. You will not perform your best or enjoy the race if you have an upset stomach or bonk.
All the extra excitement and effort of race day means that your stomach is more sensitive on race day. A gel you can stomach in training might not sit well on race day. Ultimately, you want to find fuel that works for you on race day – because that is when fueling matters the most.
For most runners, the answer is not to skip fuel altogether, especially in the marathon. A few runners possess the endurance and ability to metabolize fat well enough to forgo any calories during the race, but those runners are the minority. Most runners will find that fuel optimizes their half marathon performance (when running for over 80 minutes) and prevents bonking during the marathon. If skipping food is not an ideal option, then the solution comes down to picking a better fuel option for you.
If traditional gels work well for you, there is absolutely no reason to change them. However, if you experience nausea, the need to stop for the bathroom mid-race, cramping, or other symptoms during a race, it is worth experimenting with different types of fuel.
Gels can be difficult to digest, thanks to both their composition and ingredients. Some runners struggle to digest fructose, a common ingredient in gels. Maltodextrin is another common ingredient in gels; while it’s easier to digest than fructose, it still doesn’t work well for all runners. Whether fructose or maltodextrin, gels are highly concentrated carbohydrate solutions and require water to digest. Without enough fluids (or sometimes even with), those concentrated solutions will sit in the gut, causing GI upset and not providing the vital energy you need.
Alternative Gels: Not all gels are formulated with maltodextrin and fructose. Some brands use honey (glucose and fructose), cane sugar (sucrose), brown rice syrup (basically glucose), and/or maple syrup (sucrose) to provide carbohydrates. Some runners may find that glucose and sucrose are both easier to digest and taste better. As with any gel, you want to consume these with at least a mouthful of water – otherwise, you will be bombing your stomach with concentrated carbs.
Chews: Chews also have the benefit of letting you spread your calorie intake out more. Rather than taking whole gel every 40 minutes, you can take one or two chews every 15-20 min.
If your stomach is very sensitive, check the ingredients. Some brands use the same ingredients in their chews as in their gels. The following brands feature easy to digest ingredients such as cane sugar, fruit juice, honey, and tapioca syrup:
Liquid Options: Think beyond saccharine Gatorade here. Several new sports drinks are formulated to provide enough calories for energy without requiring much digestion.
Whole Foods: If the sugar of gels and chews unsettles you, try whole foods option instead. For some runners, the macronutrient variety of whole foods (not just simple sugars) improves digestion and prevents energy spikes and crashes. Read more on fueling with whole foods in this post.
Candy: Yes, candy. While not exactly a whole food, candy isn’t a sports nutrition product either. However, candy such as jelly beans, gummy bears, Swedish Fish, and Starburst are all options. If you do not mind chewing and enjoy the boost of sugar, candy is worth trying.
No matter which type of fuel you use, always practice before race day to ensure it works for you.
Obviously, there can be other factors that contribute to GI upset, including dehydration, chronic stress, medical conditions, or poor pacing. However, it is often the simplest solution that is the correct one: if your stomach gets upset after you eat your fuel during a race, try a different fuel.
What product is your go-to fuel for race day?
Do you use gels or hate them?
13 Responses
Tailwind was the only fuel I could tolerate and even after a while on a long run or race, I couldn’t even drink that. I think my GI tract just shuts down!
Long events can really shut down the GI system! It’s hard at the end of the race, which makes calories even more important earlier!
Great post!
I do use gels (even though I think most of them taste awful) if necessary but if I’m out by myself or during longer, slower races I like real food (like fruits and nuts) and bars. And tailwind.
Luckily my stomach is quite tolerant and doesn’t really give me any issues most of the time (fingers crossed it stays that way!).
Thank you! That’s great that your stomach is tolerant – that means you can take whatever you want for the race!
I have always had issues in the latter part of long races, especially the marathon. In my last race I walked most of the last six miles because every time I started to run I felt nauseous. I also tend to get a little hypoglycemic (hence, I think, the fainting spell I had after the first leg of my Ragnar). I rarely have the problem in training runs, which makes it difficult to figure out what is the best fuel to use. I do think I need to try something that is more sustaining, with a little protein and fat in addition to the carbs. Thanks for the great information and for linking up with us.
It is worth trying something more sustaining! While every runner is different, the little bit of protein and fat can help stave off nausea from all that sugar and from an emptying stomach. I hope you can find what works for you!
I don’t have a sensitive GI system but I don’t like the texture of GU. The chews and the waffles work really well for me.
The texture of chews and waffles is so much better than gel! Plus, they can be less messy than gels.
When I first started running longer distances, I could not find a fuel I tolerated. Gels would leave me with GI issues and chews were so hard to chew on the run. Huma Gels became my thing and then Tailwind. But most recently, all gels are fine which I’m happy about since it’s easy. Great info!
The stomach does adapt to training, which makes it easier to try more fuel. That’s great that most things work for you now!
This is great – I stuck to a single flavor of gu on race day, but I only found this out during longer training runs when I tried different flavors.
I used to use jelly beans, sometimes raisins, and then switched to the raspberry hammer gels. I actually haven’t fueled during a run in a really long time now so it would be interesting to see how my stomach would handle it out of nowhere.
Usually I am all about alternative fuels HS chews, home made bites/cookies — oddly enough my half PR is from a race where I ended up suffering from a mild case of food poisoning — I think, anyway, I never went to a dr. And I couldn’t take in much at the end of the race.
But it was a big downhill race and I love gravity. 🙂