Help! High Blood Sugar During Exercise

I just got back to my apartment after an extremely frustrating workout. Ok, here's the downlow:


I eat the same friggin food EVERY DAY. I inject the same amount of insulin EVERY DAY. Literally, the only thing I've been doing differently at the gym is I'm doing mainly cardiovascular-oriented workouts instead of predominantly anaerobic stuff. Specifically, I'm doing 15 minutes of cardio (on a machine) followed by 5 trisets (for those of you not familiar with trisets, it's just 3 different exercises back to back, done 4 times with no rest). I rest a little between each triset. Anyway, if anyone wants more details, just let me know.


My blood sugar skyrocketed to 295 (for no apparent reason). Usually, I drink gatorade during my workouts (4-5 per workout). This time I only drink one and a half. Furthermore, I started working out at least an hour after my last meal, for which I injected what I always inject.

All right, I could go on expressing my confusion, but I'd rather not deter anyone from reading this...


What the hell?

If the cardio part was high-intensity, that could make your blood sugar shoot up that high, especially if you don't take breaks... My BS is always in the 260s after a 5k race :/

I don't understand physiologically speaking how exercise can cause you? And is there any way of knowing whether exercising will raise or lower my sugar? Or is it just random?

Just spoke with my doctor about this… It’s a combination of the liver releasing sugar because of the exercise effort and stress hormones, i.e. cortisol, which has also been proven to raise the blood sugar. In fact, she said that in elite athletes, if they can feel themselves trending down in bs, they do a 100 sprint dash or some corollary very short, but very strenuous bout of exercise and it spikes their blood sugar right up! So, I think the trick is figuring out what the line is for you personally between exercise that just exerts, and therefore brings blood glucose down, and that which stresses, which brings bs up. I am still trying to figure it out for myself, but I know for sure that if it is sprint day in the pool, I should just figure on 300 blood sugar after an hour and a half workout!

Ok, thank you for providing me with a much needed coherent explanation. I'll definitely pay closer attention to the correlation between the type of exercise I'm doing and my glucose levels. Thanks again!

Hi Elie, I see two outcomes of exercise. At one end the sugars are likely to go up while the insulin sensitivity is also high which would mean that if u took the same amt of insulin before a work out,  that you take when u r not exercising , it should result in hypoglaecemia. While, if u reduce ur insulin owing to hightened isnulin sensitivity, ur sugars might go up. How do we manage it. I exercise regularly every morning around 7 AM to 8 AM. This includes half an hour of walking/ jogging, followed with 15 mins of breathing exercises/ yoga and 15 mins of stretches/light weights. I would then take a cup of tea around 8:15 AM. Then get ready for my office and have breakfast around 9. I am on LISPRO (Bolus) 3 times a day morning 10, lunch 6 and dinner 6, while a basal (LANTUS) shot of 26 in the night around 10 PM. Inspite of keeping my schedule almost same, i still have irregular sugars.

For example: yesterday my fasting sugar was around 126 mg/dL. Post prandial around 180 mg/dL, post lunch around 180 mg/dL, but before dinner was 250.

But today morning my fasting sugar shot up to 311 unexpectedly. I followed the same exercise and diet regimen. still my sugars are around the 200 + mark for the day.

Can you please advise.

Sambit, thank you for the thoughtful response. As far as your sugars are concerned, it sounds as if either you need to increase your boluses for meals, especially of lunch and dinner, or you need to increase your basal. I suppose it depends on how intense your exercise is and how much it increases your insulin sensitivity during the morning. Ideally, you would be using insulin pump therapy instead of injections, and it would be a whole lot easier making adjustments, especially with your basal rates. I only started exercising after getting my pump, so it's possible I'm missing something.

Thanks Elle for your quick reply. I visited my endocronologist yesterday.After much analysis here was the analysis and outcome, on an average, I am doing fine with my sugars. My HbA1C is around 8, and my doc is trying to help meget it to below 7.5, in a steady manner without causing hypo's. I had a lot of episodesof hypo's earlier around 8 months bacj. But thanks to my doc, now it rarely happens. For that, I have been asked to titrate my insulin dosage gradually after observing for a 2 3- days instead of adjusting on a momentary spike. Secondly, I do get a bit hyper when I see any high readings :)). My compain being if I maintain a good diet, lifestyle and insulin regime then why have spikes at all. For which my doc has advised to take it easy and focus more on well being rather than get too much worried abt the spikes. :)), so long i manage a decent sugar and HbA1C. I have recently started looking at pumps and have initiated talks with my docs on pump therapy. I would definitely benefit from your sharing experience on using pumps.

My first points are Animas, Omnipod, Minimed, it seems there are many brands, and that different users are comfy with diff. brands. But how to decide on which one suit one individual.

Also, how does it feel to wear a pump all the time.

IS it reallythat flexi.

Does it depend on which partof the world u r in (such as climate and weather, some countries are too cold, while some are humid, rainy and so on). Will benefit if u can give me some heads up.

Thanks a lot

Sambit, I used to wear the Omnipod. Then I switched over to Minimed. I cannot comment on Animas. How does it feel to wear a pump all the time? LIke anything else, you get used to it. I am hardly aware that I'm wearing it unless I'm thinking about giving myself a bolus. There are some drawbacks, but they are minor and shouldn't be given too much emphasis. The only disadvantage I've heard regarding Minimed is that it isn't waterproof. For that reason a significant number of people switch to Animas. I have heard, though, that the Animas interface isn't as user-friendly. As far as Omnipod is concerned, I had so many problems with it, I had no choice but to switch. The only reason I could imagine climate having an impact would be the effect of humidity on the adhesive. But the adhesive is extraodinarily strong. The only real threat to the adhesive sticking is the amount of hair on your body. Although I do not live in a particularly humid part of the world, I have had no more trouble with the adhesive on humid days than on dry days. Further, as you know from my original post, I go to the gym regularly and have not head any significant problems with the moisture on my body.

If rain is an issue, I might be more inclined to go with Animas.

Hi Elle, Thanks a lot for the information you provided. That really helps... and yes, it helps to relook at all the parameters since we tend to look at things with our own perspective and the sales info / videos provided on the web.

When I went thru the online demos, I observed that Omnipod was water resistant and that you only need to apply the patch, rest is easily installed using the PDM (which looks like an iPod).

While both animas and minimed look a bit bulkier and one needs to do the installation using the infusion set manually. Not sure how much difference it makes.

Also, I am looking for a system where I can not only use the pump but also regularly check sugars that would get be recorded in the system that I can easily trace back. and that the pump would be able to advise the bolus and basal based on the carbs and past sugar readings. Here too, I think Omnipod has the advantage of user friendliness as all that data seems to be recorded in the PDM.... and no need to even press the button manually for the bolus since that too is remote controlled by the PDM. However, it seems that you did not find it easy to use practically. Can you let me know  if there were any drawbacks with pmnipod ir was it some other reason that u switched over to Minimed.

First off, I'm not aware of any system that takes into past sugar readings. All the adjustments must be made by the user. If you're looking for some kind of correspondence between the glucometer readings and the pump, all three have that capability. Omnipod combines the two in one. The other two - I know this is true at least for Minimed, pretty sure for Animas, too - are wirelessly connected. With the Minimed, I use the Carelink software, which allows me to upload all my glucose readings, boluses, etc to my computer. The software compiles all the data into various tables, which has proven helpful.

Why did I abandon the Omnipod? (1) Well, it malfunctioned frequently. On countless occasions the pod simply stopped working, made an incredibly high-pitched sound, signaling me to remove it and put on a new pod. This always happened well before the recommended 3-4 days. (2) The pod didn't insert the needle/catheter well. Although it sounds ideal to let the machine insert itself, a machine can never outperform a human being. Different parts of the body require slightly different techniques, angles, depth, etc. Perhaps it sounds like I'm being a bit nit-picky, but the reality is diabetes care is ALL about fine-tuning, learning what works the best.. (3) The pod is much, much bulkier and more prone to getting knocked off. It's also larger and more visible, which isn't something I ever cared about but something a lot of diabetics consider. (4) The main reason I chose Omnipod in the first place and probably the main reason most people choosing Omnipod choose it: it has no tubing! Well, I have been using the Minimed for a few years now, and I couldn't care less about the tubing.

countless occasions is an oxymoron, isn't it lol

Thanks Elie for all the information. I would study the pump market before taking a call on this. Would lok forward to better technology as well. :)