Kpanda’s running highs and lows

Hi folks! I haven’t posted much lately, but have still been quietly snooping around. But I’m back with an exercise/running question! I know there are tons of great exercise and running threads around, so I apologize if I’m asking a question that’s already been covered.

Anyway, I run a handful of times a week, normally. Usually nothing too intense, just a 3-4 mile jog. On weekends I usually go before breakfast (I’d prefer to be able to eat first but I am trying to get used to running on an empty stomach). Weekday runs are usually after work and I just avoid carbs after lunch so insulin on board is minimal.

Ok, sorry for the novel before even getting to my question, but sometimes I just can’t plan my day around insulin on board. A morning run was out of the question this morning, but I really needed to get my run on today. The best time to get it done happened to be 2.5 or 3 hours after a breakfast disaster and my BG was something like 80 but dropping slowly. I ate some slower carbs, thinking that would hold me steadier during my run than fast carbs, but that didn’t bring me up much and I needed to get out the door, so I added a few fruit snacks to the mix.

I headed out to run at like 90 and barely going up, and held mostly steady, but had a few more fruit snacks toward the second half of my 4 miles as I was starting to trend down. During the run things were great, and then I stopped running and all those carbs hit me, maybe combined with some adrenaline from trying not to die running 4 miles in the sun/heat, and things went a little haywire. I spent several hours higher than I wanted to be, and avoided carbs all afternoon because I couldn’t get my blood sugar down first.

All this to say, what the heck should I have done instead to avoid or deal with the post run high? Aside from just picking a better time to run… I hadn’t exercised since Monday and just had to squeeze it in. Ideas??


During exercise, blood is diverted from the digestive tract to the active muscles, which slows down the digestion.

Added to that, the nature of things like fruit snacks during exercise can also be slowed down by the lack of available water. In your body, water moves across the membranes in the direction from higher water concentration to lower water concentration. If you are eating a dried fruit snack, the delay in digestion is because your body needs to be able to provide enough water for that snack to be digested.

So your body is diverting it’s energy to the muscles and your digestion is put on the back burner.

On top of that, as you stated it was sunny and hot, so your body is a bit dehydrated, and that slows down your digestion.

You were only are getting some of the carbs you were eating while running. You kept needing to eat. As soon as you finish, your digestion starts to pick back up, and as you re-hydrate, all of that stuff you ate hits! And on top of that, you had slower carbs too, so those were also added to the mix.

What I do:

  • Try to stay hydrated when running, and if possible treat lows with a drink like Gatorade. Drinks will generally work faster, especially when running and when dehydrated.

  • During runs I treat with small amounts of fast carbs. A little before starting, and then as needed.

  • After every run, I take insulin and carbs. No matter how low I am, I take insulin and carbs, every time.

Since you are on a fixed basal and can’t reduce it, you should plan on feeding that basal during your run. Don’t try to take it all up front before the run. Just drink small amounts throughout your run.

They design drinks like Gatorade and Powerade to be absorbed faster than other carb sources during exercise (even though a drink with an even lower osmolality would work even better than Gatorade).

Hope my answer makes sense.


As Eric said, your body has other priorities than digesting food while you’re engaged in exercise… it’s pretty standard for carbs you eat while running to just stagnate until your body is at rest. Eric can give a lot more technical exercise advice than I can regarding carbs and exercise and metabolism…

I just generally don’t worry about it that much when I exercise. When I was using Lantus for basal (which despite what you might read on Internet, is same exact thing as toujeo) is have to snack a little to get my blood sugar trending upward before I started running. With tresiba, what I use now, I just try to ensure there’s no significant bolus on board when I start (for me this means 3+ hours since blousing generally… longer with higher doses) and it seems to work out ok…


Thank you both! This is great info to think through.

So, I probably need to update a profile somewhere on here because I am using the Omnipod as of a couple months ago. So I actually COULD reduce it. Everyone says that’s one of the beauties of pumping as it relates to exercise, but I’ve not tried it yet. I feel like I’ve read that it takes a while for the reduction to have an effect. Is this true? If I’m just going to spur of the moment run out the door, is it too late at that point?

I am happy to report that this morning’s pre-breakfast, cloudy, slow jog had predictably much less frustrating results :slight_smile:


Do try it! I worry so much less about exercise related lows now—even for activities like lawn mowing! I usually reduce my basal rate about 1/2 hour before activity and the percent reduction depends on my recent BG level and trend info as well as the type and duration of activity. I have been keeping notes on the adjustments I made and results. Sometimes I have had to adjust settings on the fly and take on quick carbs to stay in a safe range.


Oh, that’s right. I remember posting about that now.

Okay, so it always depends and is different for everyone, but a very general starting point to try would be turning off basal 30 minutes before and then leaving it off for the duration of the run.

Of course as CatLady said, it depends on if you are high or low, trending up and down. So what I said is just a very generic suggestion that you can tinker with.

Start with that and see how it works for you.

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You can at least turn it off then. That would help.


I am sort of like you @kpanda01 where I can’t always plan my run time. I’ve started using @Eric’s suggestion of doing ZB half hour before my run and it has really, really helped w/ the lows during a run which was almost impossible to prevent before. I reactive my normal basal before I finish the run though to help w/ the highs I usually get after running. So 2/3 of the run I have no basal. I’m also using Omnipod.


I’m weirdly excited to try this now! Morning runs before breakfast don’t seem to give me much trouble, but I’m going to give the reduced/zero basal a whirl for my next afternoon run… i’m interested to see how it goes! And I’m intrigued by CatLady’s suggestion for using the same for things like lawn mowing - which who am i kidding, my husband does - but I do the other yard work while he mows, and I’m interested to see how this works for things like that as well.


Went for a super short 2 mile jog after work and decided not to experiment with basals for such a quick run. Went a little low anyway, but oh well. I took my pup with me and it poured down rain, but I got to loosen up my tired legs and he got to frolic in the rain, so it was a win anyways :slight_smile: Guess I’ll play with the temp basal another day!

“Geez mom, quit with the photos already!”


Awww, love that photo!! That’s a keeper, what an expression! You’re a good mom:) Worth the 2 miles, slight low, but happy pup:)

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So I’ve been experimenting with reducing basal ahead of my afternoon runs and don’t have it totally worked out yet, but I feel like I’m getting there! It feels good to feel like I have something to work toward!

I feel like I saw this mentioned in another thread here in the last day or two but now I can’t recall which thread. But for those of you who reduce or stop basal during exercise, do you find you need extra bolus with your next meal to make up for what was missed during the temp basal? Or does the effect of the exercise negate that somewhat?

If you consume carbs during exercise do you find you need to bolus for some of those afterward, or does the exercise pretty well gobble those up too?

I ask all this because my dinner last night (post run, after a couple hours of minimal basal) spiked me more than I would have expected. Of course that’s just one day and I need to experiment further! But I used to be able to cut way back on bolus for meals after exercise, and lately that hasn’t been the case, which is frustrating… feels like the exercise is having no effect at all! More work to do…!

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Lots of good questions here.

I do think that it’s a good idea to replace the lost basal. But the amount depends on many factors, so it takes experimentation to figure out how much.

Consider these things on how much lost basal you want to replace:

  • how hard was the run
  • how long your were at zero or reduced basal
  • carbs consumed during the run

The harder the run, the less :arrow_down: basal you will need to replace (up to a point, a very high intensity run can cause a big spike, let’s cover that in a different topic)

Longer time with zero or reduced basal means more :arrow_up: basal will need to be replaced.

More carbs consumed during the run means more :arrow_up: basal will need to be replaced.

Also to further complicate things, how soon you are eating afterward makes a difference. If you are eating right away, you may not need to replace as much basal, because your meal bolus will probably be somewhat amplified. But if you are not eating right away, you are just riding on empty and so in that case more basal replacement might be needed.

This depends on at what point you eat them, and how much you are taking, the type of carbs, and how hard your body is working. Again, it depends on many factors!

Exercise will cause your body to use whatever fuel (fat, carbs, or muscle glycogen) you give it that it can most easily process. And which fuel it uses varies depending on the exercise.

  • If you take in a very fast carb (high glycemic index), your body will immediately use anything it can take from your small intestines and pull the glucose into the cells for energy (this is called glycolysis).

  • If the carbs are harder to digest, they may not hit you until your workout is over, and this can cause a post-workout spike.

  • If your workout is slow and easy, your body will use mostly fat metabolism, and the carbs may spike you because your body may not use as much for the run.

  • If you are working very hard, your body will put digestion on the back-burner until the exercise if over. This will slow digestion, meaning you may drop during the exercise, but spike afterwards when the carbs start to get picked up.

  • And if you are working extremely very very hard, your body will use liver glycogen, which will immediately spike you.

So, at this point I should stop, because I am worried that because I am not answering your question, you will just think
"Eric = :question::confounded::question: "

Really the easiest thing to do to make sense of it all is work through a couple examples and experiences and try to identify the reasons for what happened.

So if you want to try that, just post a quick synopsis - I started with this BG, cut basal for this long, ran for this long, the run was X on a scale of 1-10, I had __ carbs, and I ended up with a BG of __

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Great feedback - thank you! I think I do need to start tracking some of the details in order to work this out. I knew that before I posted, but was frustrated and impatient and thought I’d go ahead and ask even though trial and error is probably going to be the answer :slight_smile: thank you for the guidance though… I’m probably not going to get in another run until Thursday, at which time I’ll try to make some notes and report back!

On a related note… would you say energy gels are a better fast carb source for a run than something chewy? I usually toss gummy fruit snacks in my pocket because they are so portable but I can see how liquid would work faster. Although I agree Gatorade would be ideal, I kinda despise carrying a drink around unless I have to. I’m thinking gels are closer to liquid?? What about those little kids applesauce pouches? I used to use those for fuel during long runs. Those are probably pretty quickly digested?

Glucose is absorbed in the small intestine. Liquids only need to be broken down chemically. Solid foods need to be broken down both structurally and chemically, both by chewing, and also by the stomach.

So liquids will always be fastest for exercise.

But … gel pouches are pretty quick. And I agree they are easier to carry than a bottle of something like Gatorade.

While running gels are generally horrible to eat because it’s like eating toothpaste, the Huma gels are not bad at all.

Try these instead. These have the ideal mix of glucose to fructose (2:1 ratio) to maximize uptake, so they absorb really well. They taste pretty good, and they have lots of different flavors to choose from, depending on what you like.


i am a swimmer and cannot wear my MM pump in the pool. i have to prep with ZB for 2.5 hours BEFORE i jump in the pool. i get out every 1/2 hour to do a finger stick and to see if i need some carbs to continue swimming (depends on my BG at the time, and how far i am into my ZB).

when i am done, i havent had any basal for 4 hours, so i bolus to make up for the missed basal. this keeps me from spiking after my swim once i reconnect. then i bolus 50% of my fast carb/protein shakes (2 Glucose Control Boost shakes which have a total of 32gms of each for protein and carbs and only 4 gms of sugar)

this has been my formula for (almost) a year now, and it was eric with came up with it. we did a LOT of experimenting over the past year, and i needed to be patient as well as a cooperative student. but it has all worked out in the end.

if you want to read about my journey, i have a site devoted to it (Daisy Mae’s Swimming Thread)
perhas that might be helpful; dont know for certain b/c running and swimming seem to be very different on the body. just be willing to have patience and to be flexible.

hope this helps some. above all, though, trust eric!! he knows his stuff and he’s a runner too.

Daisy Mae


Will look for these! I like that the ingredients look like mostly real things… which is why I used to use applesauce over some of the other available stuff! Good tip!

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Thanks for your feedback! I have read bits and pieces of your swimming thread and am in awe! I am quite sure your “have patience and be flexible” advice will serve me well. Can’t say I’m always good at the patience thing, but I’m willing to work at it! :wink:

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all you ever need it to be willing!


I was pretty excited to experiment with a temp basal for my run this afternoon but got busy and distracted at work at the end of the day and didn’t get the basal turned down as early as I’d planned.

I turned it down by 75% (25% of normal) about an hour and a half before my run. Started running at about 120 and sorta steady (had just leveled off after going up a bit). After a mile I was still pretty much steady. Started going down (90s and dropping) at about mile 2, so I took about 6g of carbs, followed by 4g more after about another half mile.

I did 4 miles total, which I was happy about since I only set out to do 3! And I finished with my BG at a steady 78! Wish I hadn’t needed a bunch of fruit snacks, but glad I got 4 miles in without going low. (P.S. I ordered some of the Huma gels, but am sticking with fruit snacks until they get here!)

I bloused for the extra carbs when I got home because I saw my BG creeping up, and ended up eating dinner only 30-45 minutes later. I probably should have skipped the first bolus bc I’ve been trying to avoid going low ever since I ate.

I think next time I’ll dial back the basal even further, or start the temp basal sooner. Not sure which. And I need to get more organized about my post run meal! Stay tuned… (exciting, I know you’re on the edge of your seats, lol!)