Exercise, Lows and Type 1

So, I’m wondering if any type 1’s could share their insulin dosing while exercising. I’ve recently really started exercising again, long hikes with inclines and tennis. I’m having a horrible time with lows, lows that last 5 - 6 hours after working out. My CDE suggested eating an apple 15 - 30 grams of carbs from an apple as it has fiber, 1 hour prior to work out. I still am dropping. I’m working on getting back on pump. But, how does one do this on MDI? I’ve already cut my AM levemir back to 2.5 units AM and 4 units PM, last night I woke up at 4AM at 55 and .5 unit corrections are dropping me a lot now too.

Also, do any type 1’s have issues with really dry skin, eyes, mouth, etc…I drink a ton of water but I always am so dried out, my skin, etc…I sometimes think it’s from levemir, I don’t know though???


hi sarah,

i would not eat an apple an hour before a long hike. i would probably start the hike eating something like an apple though. along the hike i would top up with some glucose tabs as i went along and get some fat in there as well so i just didnt burn through the glucose. my favourite thing about doing exercise for an extended period is how much food i get to eat! if youre going on a long hike with inclines, youre going to need more than 30 grams of carbs i would think.
if i do a long bike ride or a long hike, i might lower my levemir that night by one unit-i take 8units in the am and another 8 in the pm. but i would more likely eat a snack with carbs and fat/protein before going to bed. can you tell i love eating?
aside from the lowering by 1 unit that night, i usually dont do anything to the long acting. im quite active every day, so its pretty consistent. so you take short acting for meals? maybe cutting back on that for your meals during the day of your hike?

tennis, i dont know, as its a lot of start and stop, and i dont do any activities like that.

i have dry eyes when i wear contacts and dry skin, but i think thats from getting old-big 4-0 in december…

thanks. I had the worst time with the tennis. I don’t know. I only played an hour. I thought too that I needed something with protein. It was just scary because I just stayed low for 5 - 6 hours afterwards, kept having to down glucose tabs. Do you adjust your I:CR after activities. I think I needed to do that too.

You might consider purchasing Sheri Colberg’s book “Diabetic Athlete’s Handbook.” Lows after exercise are likely caused by two things, increased insulin sensitivity and post exercise hypoglcemia. To deal with increased insulin sensitivity on MDI may require planning. Dial back your basal ahead of time for 12-24 hours and then add back in additional rapid at meals as needed. You might even find that with a long day of hiking you can actually skip your basal. Exercise raises GLUT4 activity, a parallel and separate path from insulin for glucose uptake.

To deal with post exercise hypoglycemia I found the best solution was a good meal with bolus within 1-2 hours after exercise. If you get post exercise hypos like this they will be different. Once I had to take 100g of carbs to deal with it. This seems to be a sudden surge where your body tries to replenish depleted glycogen stores all at once.


hi sarah. i think i am lada as well-never got a differential diagnosis, just t1. ive had it for four years and i hate fast acting insulin and the limits it puts on daily life. so i always try to fool my diabetic body into thinking no fast acting is necessary.

for example, if im going to cycle 7 km to work and my bs is 100, ill eat some carbs with lunch to make sure i dont go low on the way, test when i arrive and depending on where i am bs-wise, eat carbs if necessary. if im 160 before lunch and the ride, ill have only a salad and my bg will usually go down with the cycle. i just try to avoid fast acting.

after 4 years, its getting quite dicey and sometimes i have to inject to eat even though im going to be exercising afterwards. some mornings i do a cross-fit type workout and run and i ALWAYS go high now from it if we cross-fit first, so instead of my egg and veg omelette, i have some carbs and inject for most of them. the rest of the insulin is used by my body to bring down the spike from the high intensity exercise. i hate injecting for exercise because sometimes our running coach starts the session with running, which lowers bg and i have to be extra vigilant.

i look at my running friends and im amazed at how their bodies do it!

I take less fast acting insulin on the days that I exercise, both before and after exercising I leave basal alone. I have far fewer lows since I eliminated grains, lowered carbs in general, and increased healthy fats in my diet.

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Thanks for another book recommendation. I finished Dr. Bernstein’s book “Diabetes Solution” I got a lot of information out of his book. I have been having the same issues with exercise and low’s so I will get this book to give me ideas to get this under control.

on Mondays I am in a Box fit class for 45 min after supper. when I calculate my bolus for supper I reduce the amount of insulin by 30%. I do have to make sure I have protein with my meal.

If exercising in the morning (7AM) would that mean lowering basal just after dinner and then going to bed high? If exercising daily will this not lead to difficulty controlling BG within range?

I workout 5-6 times a week. I won’t workout if my blood sugar is below 80, even when it’s 80-100, I will eat a little protein beforehand. However, when I lift weights, my blood sugar ends up rising, and doesn’t start dropping until a few hours after my workout. Maybe my body is just messed up :frowning: