February 7, 2024 - Maltodextrin

I may have found a common factor, a known gastrointestinal distress factor, in the marathons where I have experienced the need to stop and poop. Maltodextrin! From what I understand so far, there are good reasons many engineered nutritional products use maltodextrin as the primary carbohydrate source. However, there also seems to be some research that suggests for some people, maltodextrin basically acts as a laxative. 

When I first considered this, I thought maltodextrin wasn't a common factor. At Miami Marathon, I used UCAN Edge gels which do not use maltodextrin. However, I also relied on the on-course hydration drink, Gatorade Endurance. Gatorade Endurance does use maltodextrin. In a potentially frustrating twist, Gatorade Endurance actually works for me quite well. I can drink it for hours and not get sick of it. It doesn't cause me any nausea. It has functioned well to keep me hydrated and not apparently short on electrolytes. I've really liked Gatorade Endurance. However, I can also recall many occasions when I used it heavily during a long training run, then ended up in the bathroom for an extended period once I got home. 

At CIM, I used Maurten gels which do not contain maltodextrin. And I used on-course nutrition again, Nuun Endurance, which also does not contain maltodextrin. I thought I had hit a dead end. However, I had forgotten that I drank a Maurten 320 drink on the bus to the start line. While the Maurten gels do not use maltodextrin, the Maurten drinks are heavy with maltodextrin! A common thread!

And as I think back on other recent races, I can find other products containing maltodextrin being used by myself. The only outlier, Jacksonville Marathon 2022. I believe I used Maurten gels during the race, but also drank Gatorade Endurance on course...so maltodextrin. And I did not have any GI distress. But there may have been a mitigating factor. The weather was wonderful. Cool, not terribly humid, just very nice. And that resulted in me electing more water at water stations than Gatorade. Generally, I will alternate between water and on-course hydration drink from water station to water station. In a hot race, I'll take the on-course hydration product more frequently, like two out of every three water stations. And in a cool, low sweat rate race, I'll lean toward more water and less on-course hydration drink. And, in fact, I'm not even sure Jacksonville Marathon uses Gatorade Endurance. They may use conventional Gatorade Thirst-Quencher, which does not use maltodextrin. 

So, I think I've identified a common factor in marathons with GI distress. That doesn't explain why it does not happen in ultramarathons, but this could come down to something as simple as the much higher pace and aerobic output required of marathons, even when pacing. This may not be the full answer to my challenge, but it may be a part of the answer. And it's a pretty simple thing to test...just remove all maltodextrin based foods and drinks from my diet and see what happens. 

Simple, but a bit difficult to actually do. Such a majority of the engineered nutritional products use it that it will require some work to avoid. And it will become particularly tricky when trying to rely on on-course hydration during marathons so that I don't have to carry my own liquids. But a worthwhile exercise despite this little challenge, I think.