Nutrition Mistakes During my Marathon Training with Type 1 Diabetes
The miles, the duration and the intensity of my running workouts increases, and as my first race approaches (Verona Half Marathon) I am using my long runs to test various nutrition strategies to assess the impact on the performance and on my blood glucose and insulin needs.
Nutrition strategy overview
For workouts that last 2+ hours, I typically do this:
During the 36-48 hours leading up to the run, I carb load.
I eat around 10 grams of carbs per kg of bodyweight (in my case close to 650 grams a day).
I eat the bulk of it earlier on in the day to avoid large dinners that could affect my digestion and sleep.
I tend to avoid fibrous foods, moving away from my typical green light foods (like whole rice or whole pasta) towards yellow light ones (like white rice or white pasta). 95% of the time I eat clean whole food plant based green light foods. There’s a 5% of cases where it makes sense to eat less fibre, and long runs belong to that 5%. If the body is insulin sensitive to begin with, it will not be a problem.
The morning of the race/long run:
I eat a small breakfast one to two hours before the start just to top up my carbs. I used to do oats and peanut butter but I don’t anymore: oats contain a fair amount of fibre and peanut butter mainly contains fats and proteins, both of which can cause tummy upsets. Following Patrick’s advice, I lean on something safer for my stomach, such as rice cakes with some jelly and nothing more than that, the carb load should have been done the days leading up to this moment.
I drink coffee.
I eat one gel per hour while I run (around 30g of carbs per hour). If I am running close to three hours, I will aim at 60g of carbs per hour.
The strategy works, but type-1 diabetes has its own several moving factors which are at times tricky to handle. I still make mistakes from time to time, but I am figuring that out step by step! Here are the latest!
Not experimenting running at different times of day
I like to run fasted in the early morning. That is the safest option for me, because not eating means I don’t have to inject anything, both of these things being additional risk factors. I must be realistic, though: if I want to perform, the day of the race I will not run on an empty stomach, and I must be able to manage my carbs and insulin safely and without hesitations.
I have thus put my beloved fasted running on hold, at least for my long runs, and switched to “race mode”, simulating race conditions. If I know that on the day the guns will shot at 8.15am, I will make sure I start at that time and with some fuel in my belly.
I also put some runs in the late afternoon, after a whole day of eating and injecting, to train myself further to run with insulin and food on board. These variations in the routine are essential and serve two functions:
training my stomach to run with some food in it,
observing how my blood glucose reacts.
This is crucial intelligence to collect in the months before the race, because they allow me to get accustomed to managing injections and glucose in the blood without risking compromising the race.
Experiment early on to go on autopilot with no hesitations on the big day.
Fearing hyperglycaemia and injecting too much insulin
I know that the process I have outlined above works. It is math, and it is inevitable: if you track your food, your injections and log everything, it really is only a matter of doing the calculations. I love being rational and at times I wonder whether being a robot would suit me better, but for the time being I am a human with all human shortcomings.
One of these is giving up to fear and acting in suboptimal ways despite knowing the “right way”. In this particular context, this means: knowing the exact amount of carbs to eat, knowing the exact amount of insulin to inject, and still injecting the wrong amount.
Eating carbs while reducing insulin can sound scary because it can easily lead to a high blood glucose. That is true in most cases, but if I have done my work and have an insulin sensitive body, then I should not fear this as much. The running itself will make up for the missing insulin, and blood glucose will stabilise naturally.
The reminder to myself, then is: you ate the right way, you logged everything, you did the math. Being scared is natural, but sticking to the numbers is your safeguard.
Eating too much fibre
It is no secret that I am a strong advocate for a plant based diet centred on whole foods that are rich in carbohydrates and naturally low in fat. That is what the Mastering Diabetes approach recommends, and I could not recommend this approach enough. These are the foods that make you insulin sensitive - an increased time in range being the mere logical consequence.
I derive the 90-95% of my diet from these “green light foods”, but long distance running, like any kind of endurance feat, is a beast of its own kind. Too much fibre in the days and hours leading up to a long endurance event will inevitably cause some stomach upset.
I consider myself “well trained” when it comes to fibre consumption, but the longer and the more intense the effort, the more we advance into unknown territory. Being in the realm of the unknown, our tummy might start to react in some funky ways, and we need to work in advance to avoid that.
I still consistently fail on this point because I like my dinner to be a large salad full of vegetables and legumes, but there’s a time and a place for lower fibre, and long runs are one of such cases. To be clear, there are many ways to reduce fibre intake, many of them are wrong - less fibre does not automatically imply feasting on junk food.
You can still do this in an healthy way: what I do is replacing my big salad bowl with some white rice, pasta or potatoes accompanied by a small portion of greens to help control potential blood sugar spikes.
At the end of the day, when your diet is spot on 90% of the time and your body is trained to use insulin efficiently, one or two days every couple of weeks or months will not put your health at risk.
I mean, it could be worse.
Slamming down too many carbs the evening before yourself the evening before
When I type keywords such as “marathon carb loading” on YouTube, I am exposed to hundreds of videos of people eating tons of pasta the evening before their race. I’ve tried that for some of my long runs, and I am lucky to have done that during training because had I tried this solution for an official race, I would not have crossed the finish line.
Three things happened when I tested this approach:
My BG was impossible to handle. I had a big spike overnight, which caused me to wake up to inject some corrective units in the middle of the night.
My sleep was severely disrupted not only because I had to wake up to inject insulin, but even more due to the fact that an heavy dinner puts the digestive system under great stress, and all that stress simply makes falling and staying asleep very, very hard.
As you can imagine, the combination of rollercoaster-like blood glucose and lack of sleep made controlling my diabetes variables pre-during my run ten times more difficult. All of a sudden, I had to think very hard to manage what is normally “business as usual”: how many units should I inject to bring my BG down? Should I inject at all? What if I inject too much? And should I eat my gels with such an high blood sugar?
Not only am I eating more refined carbs than usual - this alone is enough to disrupt optimal blood glucose levels. I am also doing it right before bed time, the part of the day when we burns less energy. Doesn’t sound like a good idea to someone who cares about their type-1 diabetes and their running performance.
In other words: a heavy, carb loaded dinner made everything much more difficult.
As I said earlier in the post, I focus on eating plenty of carbs (10 grams per kg of body weight) in the 48 hours leading to the event. And I design my meals so that I reach that goal as early in the day as possible, so that my dinner can be fairly light. It’s still a lot of carbs, but with enough planning I could avoid or at least contain the negative side effects.
Running with type-1 diabetes stimulates me like crazy because I get to figure out so many things about how my body works, and I find that to be a great opportunity to take charge of my own health.
As you can see, it is not a smooth ride, but every hurdle is a chance to make things better next time. I hope you found some insights in my experience, and I look forward to hearing your experience. You can drop a comment below, I read and answer to all of them!
Have a great week, see you next Sunday!
