Training for a Half Marathon with Type 1 Diabetes - ExpressionMed

Training for a Half Marathon with Type 1 Diabetes

July 14, 2023

Training for a half marathon with type 1 diabetes

Running a half marathon has been on my bucket list for a long time, but thinking about running 13.1 miles straight while considering my blood sugars always held me back. I was worried that I would have a hard time keeping them in a normal range for that long without going dangerously low and having to stop. But, I was set on accomplishing this, so I needed a little bit of help.

I signed on to work with a registered dietician and diabetes educator with Your Diabetes Insider. Not only do they work with people on managing their blood sugars and lower their A1C, but they also help people with diabetes lose weight and accomplish athletic goals like running a half marathon. Ben Tzeel, my personal dietician, helped me right away to figure out what I needed to do in order to maintain good blood sugars while increasing my weekly running mileage.

Insulin On Board

The first thing I learned to consider was insulin on board. I use the Tandem/Dexcom G6 Control IQ system for my diabetes management. Because I like to run first thing in the morning, insulin on board wasn’t always something I considered. Sometimes if the mileage is short enough and my BG is over about 110 mg/dL, I’ll run without eating any food beforehand. However, as the mileage went up, it wasn’t necessarily responsible to run without having any food in my system. 

Based on advice from Ben, I would eat between 15 and 20 grams of carbs about 15-20 minutes before my run. I would take insulin for about half the carbs I was eating. This would prevent me from spiking in the beginning of the run and keep me fueled without causing a low blood sugar. Most of the time with this method, my blood sugars would stay very steady throughout the entirety of the run.

If I wanted to run at a different time of day than the morning, I needed to take a look at how much insulin I had active before heading out. If there was any insulin on board before I headed out for a run, I was likely to go low, so I had to make sure to correct with a little bit of carbs beforehand.


You’ve heard it from every doctor, nurse, endocrinologist, and diabetes educator out there: “Take your insulin 15 minutes before you eat!” For 16 years, I never listened. I didn’t care. I wouldn’t take my insulin until right before I ate, or even as I was eating, and I would inevitably spike right after the carbs hit my system. 

After I started working with Ben, I started pre-bolusing, not thinking it was going to help. Let’s just say, all those doctors, nurses, etc. knew what they were talking about. My post meal spikes became few and far between, and I was able to keep my BG in range for several hours after a meal. What does this have to do with half marathon training you ask? Everything! Having good BG management throughout the day means not only do I feel better during the day, but I sleep better at night, and therefore have way better runs in the morning.

During Run Fuel

Most avid runners will recommend different types of gels and chews for 30-40 minutes into your run to keep your energy up. Unfortunately, most of these products have a ton of sugar in them. If I ate them on the run, it would be fine at first. But, within 15 minutes of finishing the run, my BG would spike to 300 or more! I then decided to start using UCAN Edge Gels. Ben highly recommended them, and they’re sugar free! They give me the energy I need to finish a long run strong without affecting my blood sugars too much.

Post Run

After a run, the last thing I want to do is eat. I used to finish a run and then not eat for several hours after. I would then be exhausted the rest of the day, feeling nauseous, and I wouldn’t be able to do anything else the rest of the day. 

One thing Ben taught me was to replenish my electrolytes and get a good protein source in as soon as I finished a run. I started having a Gatorade Zero right when I got home, and I ate a protein bar before I hopped in the shower. I also prepared for long runs by drinking Bodyarmour Lyte the days leading up to the run. This helped me not get nauseous and allowed me to do a whole day of weekend activities after running 8, 9, or even 10 miles that morning.


The Dexcom G6 has been a game changer when it comes to running with Type 1. Not having to stop and prick my finger in order to check my BG in the middle of a run is huge. Unfortunately, the adhesive doesn’t always want to stay on through a sweaty workout. I’ve found that the only tape to keep it secure for the full 10 days is ExpressionMed! They come in skin tone (my favorite) plus some really fun designs (Someone has even complimented my Dexcom as a "cool tattoo"). 

I also utilize an apple watch while I run. Not only does it track my distance and time; I’m also able to check my blood sugar on it as well. This makes it so that my phone can stay safely tucked away in my runners belt throughout the whole run.

Final thoughts

After putting in the work and training for several months, I was able to complete the Grand Tetons Half Marathon in June 2023! I attribute my success to Ben with Your Diabetes Insider being so available to me throughout the process. Not only did he help me with my BG management, but he was a great resource on nutrition and fueling my body properly for running long distances. I also want to thank ExpressionMed tape for making such an awesome product. Running long distances means sweating for a long period of time, and ExpressionMed tape is the only tape I’ve found to prevent my Dexcom from falling off before it’s time. 


Ready to train for your own marathon?

ExpressionMed customers receive an exclusive discount from Your Diabetes Insider! Click here to apply to work with Your Diabetes Insider today! 

Crossing Grand Teton Half Marathon Finish Line

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