Increase in BG after Exercise

I’ve recently made some drastic changes to my diet and reduced both daily calories ~1400 and carbs <50. I’m getting more frequent spikes in BG after exercise and it takes a while to get it back in range. I’ve read info that exercise causes release of adrenaline and cortisol, which in turns causes liver to dump sugar. Also have weird feeling in muscles. Hard to describe. It happens about a third of the time, where as on my bad diet, it usually only happened when cycling. I’m not a extreme athlete and am mainly fast walking between 3-5 miles a day.

Is there something I should do ahead of exercise to prevent? Maybe carb load? Or is it just something I need to live with?

Any feedback appreciated. Thanks

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Walking usually makes my BG drop! This is, however, an excellent question for our FUD exercise guru, @Eric!

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No, you don’t need to live with that.

Sorry, a hundred questions first. Can you give me some background on the setup?

  • When do you exercise and when do you eat relative to the exercise?

  • Are you doing any basal adjustments for exercise?

  • Are you exercising because you are trying to lose weight or is it more for fitness and fun?

  • T1 now right, not T2? ( I know the LADA is classified differently, but just gauging if you are totally relying on the pump for insulin and if you have any glucagon response remaining…)

  • Are you taking anything like metformin?

  • Gauge your exercise on a scale of 1-10 in terms of how hard it feels. 1 is taking a nap and cuddling with a kitten, and 10 is running as hard as you can being changed by a lion. Where does your exercise fit in there?

  • How long have you been doing this type of exercise routine? And how long have you had the BG spikes from it?

  • How long have you been on the <50 g diet?

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Sorry for the long replies. Hope this helps.

  • When do you exercise and when do you eat relative to the exercise? Sometimes before and sometimes after. If I’m on the low side, I will normally take in about 5-10 carbs to avoid the lows.

  • Are you doing any basal adjustments for exercise? If I eat a meal, then yes, otherwise, only post when I get these spikes. Then it’s a few hour process to get it down. Read that the released hormones can interfere with insulin. If I’m normal range before and it spikes, then it usually take a minimum of 10 units to bring down, and that will still be a a few hour process. Other times, it goes down, which is typical.

  • Are you exercising because you are trying to lose weight or is it more for fitness and fun? All of the above. Been doing this for years, but up to this point, not a great diet or DB control. Therefore, large weight gain.

  • T1 now right, not T2? ( I know the LADA is classified differently, but just gauging if you are totally relying on the pump for insulin and if you have any glucagon response remaining…) T1 (C-Peptide confirmed) with a GAD test of >250. Not on pump, but totally reliant on insulin. Going to OmniPod in next couple of weeks. Just pens for now. Educator told me I may be more complex then a person who has a complete burnout of pancreas and that I could have some limited and sporadic production of insulin, but that was in response of why am I going low frequently. She was perturbed when I asked if I was truly a T1. She confirmed yes and explained the C-Peptide and GAD tests. Lows appear to be from to much long acting. I’ve reduced and now getting better. Will do confirmation fasting in the coming days to set my bolus.

  • Are you taking anything like metformin? No. Insulin only.

  • Gauge your exercise on a scale of 1-10 in terms of how hard it feels. 1 is taking a nap and cuddling with a kitten, and 10 is running as hard as you can being changed by a lion. Where does your exercise fit in there? About 5-7. I pass most people.

  • How long have you been doing this type of exercise routine? And how long have you had the BG spikes from it? Years. More frequent since I changed diet about 4 weeks ago.

*How long have you been on the <50 g diet? About 4 weeks.

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Don’t worry about the long replies. You are about to go to diabetic exercise school! @Eric has never allowed being a T1 to slow him down, additionally he has a better working knowledge of the body during exercise than most physicians. Looking forward to the answers. I always learn stuff.

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Thanks for the info, Late.

A few things to start with from your answers.

Tell me about your basal. Are you using a basal insulin as well as a rapid insulin? Give me some details on your basal.

Cool! :+1: :grinning:

So this :arrow_up: definitely caught my eye!

You have been doing this exercise for years, but the spikes have increased in the past 4 weeks since going low carb. Did I get all of that correct?

Let me just say this about carbs. You can gain or lose weight with any type of diet. Total calories in vs. total calories burned. You can change metabolism and do all kinds of things with different diets, but ultimately for weight loss it can be boiled down to intake vs. burning.

I assume the motivation for low carb was for BG, is that right?

Can you give more details? Like are you exercising in the morning after breakfast? Before breakfast? In the evening before a meal? After a meal? Things like that I am interested in seeing.

Can you give me a synopsis of a typical day with a little timeline?

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Eric,

Just realized I mixed up the Basal and Bolus terms. Apologies.

No Basal before a workout. I take 20 units once daily in the am (Basaglar) then Bolus (Novolog) on sliding scale - 1 unit for 10 grams of net carbs and 1 to 30 for corrections (e.g. dawn phenom, post exercise spikes). Exercise spikes usually require a more aggressive ratio.

Sorry for the confusion.

Hope that clarifies

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Hi Eric,

Since I’m going through a bunch of changes, new diet, serious and committed approach to management and soon starting OmniPod, I’m going to start a log of when I eat in relation to exercise and try and identify any trends. I’m logging all events in Clarity so I should be identify the influences.

Once I stabilize, I’ll may come back. Thinking I may need to fuel a little more well ahead of exercise.

Appreciate your time and effort, but think I need to get into my routine and then try and analyze.

Many Thanks.

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When you come back, here is another thought. When I do hard exercise my digestion shuts down to channel all the blood to the muscles. Anything I have eaten before, particularly any extra to ward off a low during the exercise, tends to begin digesting when I stop exercising. I often have to take a small bolus after exercise for that reason or my sugar goes high from what I ate more than an hour ago.

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Yeah, good call there @Randy! :+1:

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@LatetotheParty, I have exercised fairly regularly in several different sports over the past few years. What I have found, for myself, is that:

  • some sports almost always tend to leave me low (swimming, longer distance running, soccer practices)
  • some sports almost always tend to leave me high (sprints series, high intensity training, weight training, soccer matches)
  • I have moments in my life when my response to some sports varies: I may go high or low. That is often true when I am stressed or when I lack sleep.

Once I have exercised often enough in one sport, I am always able to compensate the probable effect at least somewhat, by using food and insulin “wisely” and with the right timing. For me, dealing the more random effects is much more difficult. @Eric, I think, always knows what will happen to him.

For me, I don’t always know. I just know what I am likely to do. Some of it is that I am a teenager and more variable than @Eric. Some is also that I don’t know how to tune my exercise as well as he does. For instance, there are days when I go running, and I expect to drop a lot, but, because I ran too hard, I end up a an exercise-induced high: my bad. I also am trying to learn to feel my BG like @Eric can, but I don’t do a good job yet, in particular when I am in full violent exercise and tired.

Still, on average it is predictable after a while, I think. But don’t get frustrated when you hit a few days when your prediction won’t work!

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Hang in there @Kaelan, things got much smoother for my son after he turned 17.

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In addition to sleep, one thing I have learned is that your cumulative exercise fatigue impacts whether or not you will go high in response to exercise.

For example, suppose you run 5 miles at a hard pace, it might not impact your BG. Do it again the next day, maybe no impact.

But if you were to do it day-after-day with no recovery days, eventually the same workout would become much harder as you get more tired. And you might respond with a spike.

So it is not only the difficulty of any single workout, but also the cumulative effect of them.

It is helpful to log not only your distance and pace, but also your overall level of effort, as well as your carb and bolus amounts. Make a note of how hard or easy the run seemed, and whether your body needed more insulin or more carbs than normal, etc.

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Another thing to consider is your fuel tank.

  • If you have been eating a lot for a few days and/or not running much, your fuel tank is full.

  • If you have NOT been eating much and/or running a lot, your fuel tank is less full.

Less in the fuel tank means you are more likely to have bigger drops than you would on a full fuel tank.

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Thanks, Eric. I appreciated that coming from you!

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I noticed this in myself but it took me a long time to realize this was happening! Even now I sometimes don’t immediately recognize this effect!

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One thing you can use is TDD.

When you are eating more or running less, your TDD will likely be higher.

The opposite case - eating less and running more, your TDD will likely be lower.

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Yes, this makes perfect sense! I’m glad to hear you confirm what I am seeing! Sometimes I don’t trust myself so really appreciate knowing this is a known effect by someone I really respect!! :heart:

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Thanks for starting this thread, @LatetotheParty. Also, I really appreciate the expert advice, @Eric. I’m trying to apply this knowledge to my walking. I have appreciated what you have shared on other forums regarding exercise, as well. Please keep it up. I am “only” a walker. The nice thing about walking vs. running or team sports, is that it is easier to keep an eye on what’s happening and intervene. I admire the many runners and other athletes here. :sunflower:

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An hour of swimming like an hour on my exercise bike and my blood sugars drop. When I first switched to snorkeling/swimming for 3 hours when I added a libre and I could tell what my blood sugars were doing swimming, my blood sugars were zooming up towards the end and afterwards. Then after 3-6 times I got used to the extended time and they actually drop some towards the end.

For me the trick seems to be (for now, who knows later) I usually stay around 95-100. So I drink some soymilk which has a slower digestion time about 10-15 carbs worth wait until I go up to about 120-130. Then I swim. I had been starting to drop after about 3-4 hours . This last time because of weather conditions I hadn’t been snorkeling for 10 days and wasn’t sure what to expect. It also was really rough waters and a very strong current. I stayed even keel around 120 and when I got out I only went up to 136. I only swam 2 hours because frankly with the current so strong I was getting tired. I’m usually game to stay out until my blood sugars start to change downward but it had been a lot of work.

So this will be trickier I think coming the winter months.

Of course then I went and ate some vegan pizza…and as I am taking way more insulin than I should have needed I remember @Eric talking about a cortisol and glucogen dump that can cause insulin resistance for several hours after.

So I have a question if you know @Eric. If I drop I am getting used to the exercise and I am not getting the cortisol/glucogen dump or am I still some and that’s why I am not dropping like I do when I exercise for an hour? Or was it a sign I had a mild cortisol/glucogen dump because I went up to 136 afterwards? Does this completely go away when you get used to the exercise?

Thanks ahead of time @Eric for any input!!!

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