Blood sugar RISE after morning workout

This issue has been bothering me for a while and wanted to get some input.

This morning I woke up at 7 am with a blood sugar level (bsl) of 90…great way to start your morning! My plan was to go for a 4.5 mile run. Normally I wouldn’t run that far with a bsl of 90, but like I said I’ve been having some issues with my bsl rising in the morning. I drank a small juice box, 15g of carbs, unhooked my pump, and left. When I came home and tested again, I was at 173. I corrected for the high bsl and bolused for the banana and PB I was about to eat. I checked my bsl 2 hours after and I was at 310.

This discourages me from working out in the morning. Most times I don’t get up that high, but it does go up in the morning. And if I were to do the same run in the afternoon/evening with a bsl of 90, I would drop too low.

Has anyone else expeirenced this or have any advice?


So you were 173 and then gave insulin and…did you eat right away? I find that I have to wait until the insulin has already brought my sugar down to about 120 before I start to eat. Anyway, I have the tendency to go higher in the morning, too. I make sure that after my workout, I test, give insulin, and if my blood sugar is normal I wait 15 minutes and start eating breakfast. I’m i’m higher I wait longer, otherwise I will end up around 300 everytime. Don’t know that this will help you but it’s what works for me.

Lately, my workout at 5am is a 5k so I don’t run as much as you. Anyway, blood sugars rising in the morning might be attributed to the morning phenomenom thing, I think it happens to many people.

Even people with type one diabetes can be a little less insulin sensitive in the morning. I find that if I am up longer than 45-55 minutes in the morning without eating and dosing insulin for it (and taking my Symlin) my liver decides to dump and BGs rise high and quick. I normally eat before exercise but if you don’t want to do that I find taking a very small dose of Symlin before or immediately after exercise is enough to keep my liver from dumping. You would need to talk to your doctor about that and Symlin is indicated for meal time use so using it for exercise is definitely off label. My endocrinologist has several patients who have gone off on thier own and used it this way and he is fascinated at how well it works for us.

Morning can be a difficult time to exercise. Bernstein actually recommends that you not exercise in the morning.

Ok, given that, you basically suspended your basal and ran. What do you think would happen with no basal in the morning? Probably a rise, maybe not 173, but probably non-trivial. So you probably should not suspend your basal in the morning. In fact, I actually bolus for exercise. Keeping some level of basal during exercise particularly in the morning is probably important.

Also, once you have gone high, you can become insulin resistant, so your correction and bolus may well have been far short of what was needed to restore a normal blood sugar. And remember, if your pump has a disconnect feature, use it, when you reconnect, it should deliver your missed basal. If you just miss your basal, that won’t help.

And you may just have to accept that exercise in the morning is just too much of a blood sugar nightmare.

I stick to working out in the afternoon or evening because of this very issue. Also, I leave my pump on when I exercise. I turn the basal rate down but keep at least some insulin going into me because correcting after the fact is too hard. I’d rather go a little low while exercising than have to deal with a high later.

You are probably having a combination of things. First, Dawn Phenomenon, second you took your pump off for the run so 45 minutes or so without insulin, third simple carbs before the run and after, and lastly exercises with high intensity can very often raise your blood suger.

My blood sugars frequently go high after I ride my bike, so I usually do a temp basal increase after for a couple of hours then dont eat. However I still wear my pump when I exercise, I just turn the basal rate down for the exercise and carry carbs with me.

Good Luck.

Do you know why Bernstein recommends not exercising in the morning?
My reasoning for suspending was b/c I would be burning sugar while running. I think I need to adjust my mindset on morning workouts. I’m pretty sure my pump doesn’t have a disconnect feature, but that would be great. What pump are you using?

Yes I did eat directly after bolusing. I guess I could bolus, shower, retest, eat.

I have had this happen to me on occasion as well. I’ll wake up with a normal bsl, not eat anything, and still have it go up. I think having something small to eat, with insulin, before the workout sounds like my next step.

I’ve heard that highly intense workouts will raise your bsl. Do you know the logic behind this?

Also, I just got my first “adult” bike last week and love it as a change to running.

I used to work out in the evening. I would have problems with going low in the middle of the night, but figured out how I needed to adjust my basal. But now I have a workout partner and would much rather do it in the morning. I want my diabetes to work around my life, not the other way around. It’s frustrating that simply by moving my workout from the evening to the morning causes such a drastic change in the way your body reacts.

Many of us suffer from Darn Phenomenon (DP), our bodies dump blood sugar. Insulin can suppress this. But this “disturbance” in the morning can make attempts to control blood sugar problematic. If you just suspend your basal for your run in the morning, your body may just turn back on the DP starting gluconeogenesis and causing your blood sugar to rise, even though you burn some by running.

I don’t use a pump, I use MDI. I see that you did a suspend. Pumps are different. On a Medtronic Paradigm (if that is what you use), any missed basal from a suspend is not caught up when you resume. It is just missed. Probably another contributing factor to going high.

If you don’t normally get dawn phenomenon in the mornings I don’t think that’s the problem, and if you don’t normally need to pre-bolus before eating I don’t think that’s the problem either

Insulin absorption, even with a pump, is delayed, so I would either keep the pump on, tweak your basal settings, and have a juice box before running, or I would take the pump off maybe 30 minutes before you start exercising. I think your normal I/C ratios also assume that you have normal basal insulin functioning in the background. If you mess with your basal insulin, even for a bit, your ratios are going to be off.

You probably also do have some temporary IR if you start at 173. My advice would be to plug back in, correct your BG (and wait a while so you have steady basal insulin function) and then eat once your BG has leveled out a little bit.

Exercise makes your muscles more receptive to insulin but it doesn’t burn carbs by itself. Without some insulin on board to open up your muscle cells and let the carbs in, the carbs will just sit there not matter how hard you exercise. You need insulin to help absorb the carbs and other energy sources. Likely you had little or no insulin on board when you arose. (If Dawn Phenomenon is at play you also had other enzymes and hormones at work raising your BG.) You didn’t bolus for the juice box. After you suspended your pump (for about an hour, I’d guess), you had no or very little insulin working in your system two hours later, The correction you took didn’t account for the fact that your BG was probably rising as a result of having no basal for an hour.

The exercise puts demands on your body for energy. Having no insulin to help food into your muscles your body starts to panic and so your liver dumps glucogen in the hope of providing energy. This is a common mechanism for post exercise highs.

I don’t think you have to give up morning exercise. You’ll have to experiment a little to get it right, but try eating something more substantial than 15g of carbs before an hour run - 45g or more, and bolus for half of it. If you’re going to suspend your pump do it an hour before you start exercising so that the reduction in insulin coincides more closely with your exercise and your earlier bolus can take up the slack of the missing basal. Some people, including me, only reduce their basal instead of removing their pump and even then I only do it when my run will be over an hour. Then, resume your basal right after the run and eat something right away - carbs and protein.

While you’re experimenting always carry your meter and some carbs duiring the run - glucotabs or GU or a sports drink.

Good luck,


The logic behind this phenomenon is that the intensity of the workout sends messages to the endocrine system to do everything it can to get energy into the muscles. So the liver produced glucogen, the adrenal glands pump out adreniline and many other things start pumping out chemicals, enzymes, hormones and other joo-joo to supply energy. Unless you have enough insulin handy to move that stuff into your muscles to convert it to the energy the body is craving - you get high blood sugars.

How’s that for a scientific explanation?


I think you’re right about experimenting. I’ve been changing little by little with some success, but this morning frustrated me enough to write this post.
When you run with your pump on, what do you do with it? Pocket, clip, an old fanny pack you found while cleaning the garage?

The human body is very complex. But when it's broken down, everything it does makes sense.

You may want to check your science book on the definition of joo-joo

Intense workouts are highly stressful on the body. They are like triggering a fight or flight response. You exercise so hard that your body is relying on catecholamines to function…

I used to loathe running in the AM but am training w/ a group who go at 6:30 and it’s actually been sort of fun. I like running with people and I really like being done by 8:00. I am leery of recommending the clip I use for my pump as it blew up last weekend, right @ the end of a 10 mile run and, frankly, was not entirely free of sweat? The MM person didn’t think the button error was from the pump but you never know. I have a belt gizmo I use. I’m off to run now (obviously not 6:30 am! LOL…)

joo-joo, (ju-ju) n. 1. Magic. 2. Stuff. 3. Magic stuff. 4. Bodily chemicals that are not blood, sweat, hormones or enzymes.