Long runs: refining the approach to diabetes management

Last weekend’s long run was a partial success. I mismanaged my pre run carbs and insulin, I had slightly high BG before the run…concerned, I injected some more insulin and that caused my BG to stay up only during the first 70 minutes. After that point, the effect of the run on insulin sensitivity compounded on the insulin I had injected, and I finished my session on the verge of hypoglycaemia.

This week’s long run was even longer, and the sprint intervals made it even more intense, so I needed to carefully refine my approach. The goal was to have good blood sugar levels before, during and after the run.

So, what did I change to meet the goal?

Fixing pre-run meal and bolus insulin

First, I slightly changed my breakfast. Last week I ate my usual oatmeal and banana two hours before going out, then took one unit of insulin right before starting my run. That was a mistake. This time, I decided to slow down the release of glucose in the blood by adding a bit more fat (a few spoons of cacao powder) and protein (a cup of soy milk) to delay the absorption of carbohydrates.

I also took 80% of my total breakfast bolus, 70% of which at breakfast time, and 30% one hour after.
To translate this into actual numbers, if my usual breakfast bolus is 10, this time my total bolus was 80% of that (8 units). I then split the 8 units into two parts: 70% (5.5 units) at breakfast, 30% (2.5 units) one hour after breakfast, and around one and a half hours before the run.

I thought doing this would help me tame the possible spike in blood glucose following the meal, while still going for my long run without too much insulin on board. After taking the remaining 30% my BG was at 115.

Better, but not yet ideal

Not having enough experience on how to interpret that number (yet!), I ate a few dates for some extra quick energy. With no surprise, that produced a spike to 220 circa, which was naturally contained and lowered by the intense running. I felt very energetic during the sprints and all the intense phases of the workout, which means that I managed my carb loading better. I finished with a BG of 165, out of the ideal range (100-130), which means that there’s still some work to do regarding the management of insulin, carbohydrates intake and their timing.

I suspect that combining dates (quick carbs) with a breakfast naturally prone to make me insulin-resistant (due to increased fat and protein) is likely to be the cause. Fats and proteins made my BG stay “low” until running time. By then, I didn’t know how to interpret the 115: would it go up? down? Who knew! My lack of experience led me to be conservative and take precautions in the form of dates. The glucose in dates, compounded by the delayed release of breakfast’s carbohydrates, caused the spike.

I should have tried only one of the two to truly understand the effect of each: either the insulin resistant breakfast or the pre-run carb supplement. I will use my two next long runs to test both approaches separately.

Fixing Hydration: it’s all mental!

I also dealt with the hydration issue: this time I took a water flask with me, and it definitely helped me last more and more efficiently while running under the noon summer sun. I must say, I have realized that the biggest impact of sipping some water is really in the mind.

In fact, when it comes to hydration, the real difference is made in the hours (and days) before and after a run. You can’t expect to pour down liters of liquid while out on the streets without having some stomach issue. Drinking should be a life habit, and the more you run the more you need to drink. If you nail that, you’re pretty much good to go. To give you an example, I do sip on around 3-4 liters a day, especially during the summer. This is a good insurance policy even in the case that I venture out without water.

But from my past long run without a water flask I understood that water, even a small amount, is essential to provide and maintain the perception of freshness, which can really make a difference from a mental standpoint. And it surely did for me!
The small drops of water were just all I needed to remind my neural pathways that everything was under control and that there was no emergency going on. Reassuring the nervous system is crucial because it helps control the release of cortisol (the “stress hormone”). Overloading the sympathetic nervous system can spike the glucose in the blood, and reducing the stress factors will help control that. I am diverging here, this is perhaps a topic for another time. For now, you can dig deeper on the topic on T1Determined excellent blog post!

Lessons learned and next steps

This week was definitely an improvement. Taking all the changes into consideration, I am not that surprised that I could finish a long run with sprints under the sun, at noon, in June and in relative tranquility. The combination of reduced bolus (80% of standard dose), pre-workout snack (dates) and water proved to be a better approach to keep my energy stable and to avoid the risks of low BG I experienced last time.

There’s still some stuff to fix though: I need to figure out exactly how to balance proteins and fats before a long run. A high-carb approach has always worked well for me, and has made me incredibly insulin sensitive.
Too many fats and proteins are “yellow light” foods, and I know that consuming more of those will inevitably rise my blood glucose and probably my insulin needs. Indeed, my BG was rather shaky as a result of my more '“insulin resistant” breakfast.

As you can see, my pre-run snack spiked my BG during the run. The run itself lowered it and kept it stable during the lunch and the afternoon. However, I witnessed another spike overnight (despite a light dinner). I attribute that to the increased fat and protein consumption during the day, which increased my insulin resistance.

What I need to understand is whether or not longer and faster running (i.e. more intense aerobic activity) will tame that effect and keep everything in balance, and if I am willing to accept trading off my BG stability. I will keep trying with a slight increase in fats and proteins in my pre-run meal and see how that goes, but I am sure there’s another way around it. I just need to find it!

I’ll keep you updated on my results as I go of course, but if you happen to have any experience to share, any dos or don’t dos I should consider, please don’t be shy and put a comment below! I answer all comments!😁