I’ve run for a couple years now, but just in the past year decided to run races. I’ve run several 5ks and 10ks and am so excited about the half marathon in March. I’m not new to diabetes. I’ve had type 1 diabetes for 20 years. I wear an insulin pump and CGM. I’ve noticed when I go for long runs my BG drops low after the first hour and later goes extremely high and I end up with mod-large ketones. This happens majority of the time. I’m worried that this will be a problem on race day. I just want to go out there and enjoy every minute of the race. Does anyone have any advice on how to manage BG during and after runs? What foods to eat prior to long runs…race day?
Some more info would be helpful - what are you currently doing for fuel (carbs) and insulin before, during, and after workouts? What is the timing of insulin and nutrition before/during/after? Is there a particular time of day you're doing your workouts? How far are you running, how often, what length of time, how "intense" (these could all play into the results you're seeing). Are you monitoring heart rate? How is your hydration? How much later do you hit the highs - and what have you done in the interim for nutrition? You've got the right attitude though - enjoy every minute of the race - it's quite an accomplishment 0 and you've got a lot of time to prepare - you will be ready. One suggestion I will make at this point - do not change your race day nutrition - train with what you plan to use - if you'll be using gels/bars/drinks, train with those gels/bars/drinks - and the specific brand (and even flavor) you'll be using on race day.
I agree that 1/2 marathons are exciting! It sounds like you are way ahead of me when I ran one last year as I had a pump since 2008 but had just gotten a CGM like 2 weeks prior to the race. The IV3000 ripped off 3-4 miles into it so I lost the data stream and just winged it and pulled over and tested a couple of times. If you are running low early in the long runs, have you tried eating and cutting your bolus, like if you eat 15 carbs @ 10C/U, take 1.0U instead of 1.5? There's a chart in "Think Like a Pancreas" that's detailed but for an hour of running, I think .67 works ok? That bumps you up but you have some IOB to work on it too. I turned my basals down a lot more when I started running and, as I (delusionally? I dunno...) "got in shape", I turned them down less. Most longer runs, I turn my basal back to 100%/ normal for the last 3 miles to "cover" or at least start covering the bump that happens afterwards. I use a MM CGM and I've noticed that when I run, it runs low, even when it's not so like 5 miles into a 6 mile run, the CGM will say "60" but if I stop and test, I'll get a 95 or something so it might also be useful to test to double check the CGM if you are watching that? When I've tested, I just ignore those 60s at the end of 6 milers and crank the basal back to normal, run home and the "bump" afterwards isn't as high.
I run in the mornings. I do a couple of short runs (3-4 miles) during the work week and save my longer runs (currently 6-8 miles) for the weekends. Although diabetes isn’t new to me, doing long runs is newer to me. I typically eat 40 carbs (toast, yogurt, fruit) depending on my BG. I do this about 15 minutes before I run. If my BG is 150 I can eat that amount of carbs (w/o a bolus) and keep a steady BG for about a hour, but if I keep going it will get low. Once I stop running I don’t treat the low BG because I know it will be high later (starts getting less than 2hrs after running). Instead I check my BG frequently trying to bolus as needed to prevent my BG from getting too high. I typically don’t eat anything again until lunch. I feel like I know so much about diabetes, but know nothing when it comes to running and diabetes. I do know that I love to run, so I want to make this work!
So you don't cut the basal rate while running? I do something similar to what Acidrock23 describes (intake carbs, but with half the bolus amount), then check BG every half hour, usually eating a gel every half hour with a half bolus (less of a bolus as the duration of the exercise increases). Lately I've used a temp basal of 0 during exercise - along with the partial bolus described. Previously I had used temp basals and cut the rate by half most of the time. Again similar to what Acidrock23 does - I turn the pump back on prior to finishing the workout (or delay my post workout meal by at least 15 mins if I don't). Important part of training is the recovery (nutrition) - might want to think about doing something food-wise in the first hour (preferably 30 mins) after finishing when the body is most receptive - bolusing to cover what you eat - and seeing if that changes what happens later on.
This chart (I think I've seen it online but I always forget to save the link!) shows suggested "cuts" to both the pre-activity bolus and during activity basal rates for a variety of activities. This is always a "your mileage may vary" type of situation but if you eat beforehand, I think that it's a good idea to have some insulin to get the energy from the food efficiently mobilized into the cells. A lot of times, the "food curve" for stuff like toast seems to take about 2 hours anyway so if I run for an hour (usually about what I'm doing 6 miles in these days...) the food may still hit afterwards and not make a huge difference for the run? A lot of times, I will just have like 4 or 5 potato chips or a small handful of cereal to get some solid carbs "on board" in case I run into something but not like a full meal. I ran all summer and rarely had more than a piece of toast, even w/ the 20 milers. I might've had 2 for the marathon? I find that it's easier and I feel like I run better if I can just get my BG to sort of hover around 120 and have 4-7 jelly beans every 3-5 miles, or a swig of gatorade. I found that using the powdered stuff is 1) cheaper (3.99/ like 5 gallons) and 2) you can make custom concentrations, like 15G of carbs instead of 20G like the premade/ bottled stuff. I have a belt to lug it in and it's pretty handy.
One final thing that I found useful were Race Ready Shorts. They have a mesh pocket that's exactly the right size for a One Touch UltraMiniMeter, that I can barely stuff into the belt pockets. Having it readily accessable makes testing "on the run" easier.
Thanks so much for all the advice. It is greatly appreciated. I won't do my next long run until Saturday, but that gives me time to create a new plan. I definitely will take what you've said here and work it into my runs. I'm hoping to run 8 miles this Saturday, so I'll see if my BG improves.