May Have a Silly Question?

I am trying to lose weight but this balancing act is driving me crazy!

Before working out I try to make sure my BG is above 180 but below 230, if not I get low very quick. So I noticed when I work out sometimes my blood sugars do not go down. They do not increase either. I know exercising is not good with high BG’s because in the long run it can make you gain weight.

My question is: Are stagnate higher BG’s levels during a work out just as bad???


I’m a T1 by the way…Taking Lantus and NovoLog, for now…

I don’t let my BG get high before exercise. High BG isn’t good period. If I eat protein before working out, I don’t crash later. Really strenuous exercise sends me high with lows several hours later. Protein keeps me pretty level.

Never heard that high BG & exercise is related to weight gain. Why?

Best way to lose weight is to lower carbs.

Hi… My blood sugars usually do not change immediately after the exercise or lower during the exercise. But there is a risk of going low anytime in the next 24 hours. If my blood sugar is high (>200), I do take half the correction than I would usually take.

A lot of times, if my BG is cool when I start, hard exercise, or even moderate excercise, which is perhaps hard because I’m old, will cause a pretty significant spike when I’m done? I usually shoot to start around 110 and get it to be cool by turning my pump down and working out when I don’t have any insulin on board. I have a small, fast acting carb snack, maybe 10G of carbs every 3 miles or so and it can work out ok. Unfortunately, the planning gets dicey a lot and I’m tossing down carbs. Today it shot waythehellup and I bolused twice while I ran as the CGM hit the 160s. When I got home the CGM was @ 127 going down and my BG was 88 according to the meter. 43:06 for 5 miles though, PR! W00t!

One thing I’ve noticed is that “workout spikes” seem to go away pretty quickly? I also consider Jay Cutler stating that he was shooting for 120-180 to workout at. While I was watching my BG go up, I also noticed that I had really gonzo energy today. I dunno if perhaps the BG might have helped but it went away quickly and I had a nice evening thereafter.

I eat low carb diet…Not working alone, need strenuous exercising

Well they say when you exercise with a BG over 250 it can increase which may produce keytones. When you start getting those your body is burning the fat so when your BG gets normal again the insulin starts storing fat…I believe that is how that works…If not its something simular, Lol

How much protein do you eat? I usually eat it after…

Sometimes my body can take awhile to go down but usually I notice right away. I do have to watch out for a couple of hours later I may get low again…

I have never heard of the theory that exercise is bad for you and that it makes you gain weight. It might make you gain muscle which is heavier than fat, but far preferable.

As for the blood sugars not going down, you are producing adrenilin and adrenilin (stress, negative or positive) can delay or raise the blood sugars, but it will go down eventually. High blood sugars is not good! You never know what exercise you will be doing before you start!

Didnt say exercise is bad just not healthy with high BG for some diabetics, I am one. It can be a stressor and increase BG which can produce keytones. At that point its the same effect of those who lost all the weight before they got on insulin and then gained like 40 pounds, of course its not that significant amount but it can counter whatever you just did basically…I make sure I do not exercise with high BG but anything below 180 and I get really really low quick…

I usually stressed but I think in this case it maybe my body not getting along with NovoLog…I have not been able to get it together since my doctor switched. I plan on switching again next month. Not to mention my body doesnt follow the rules most of the time. Some days I feel fine or eaten anything I shouldnt but my BG wont go below 200 for some strange reason.

I was just wondering is if my BG doesnt go down is that a bad thing?

To answer your question, I eat 2-3 ounces of protein before exercise, usually cheese. I’m a small person, so I don’t need as much as some. If you’re doing serious work outs & resistance/weight training, you need extra protein anyway for muscle repair.

How many carbs do you eat? Low carb has quite a range depending on who you ask.

Insulin is a fat storing hormone, but it’s excess insulin that causes weight gain.

My bg drops quickly after exercise but I still don’t let myself get too high before hand. However, I will say if I’m up as high as 140 before exercise I might not correct right before exercise. But any higher, I would likely give myself half a correction. Sometimes I don’t drop right after exercise but maybe an hour or two later. I can even go high after intense cardio but I will drop later. This is another time when I may half my correction knowing that a drop is likely coming in an hour and, therefore, I don’t need as much of a correction because of that. I also find that certain exercise will cause the delayed drop – swimming and intense cardio. Other things like weight training and pilates – if I get a drop it will be during or soon after I finish and the drop is usually less. But I would never allow myself to hang out above 140 for any reason and the only reason I accept up to 140 is if I am going to exercise right then.

Gerri has the key here. Often, aerobic exercise can draw the glucose out of our blood stream and result in a quick and harsh drop in our blood sugars. One good way of managing exercise is to make sure that we provide fuel to sustain the activity. I know that everyone says that the point of exercise is to “burn calories,” but I’ve come to the conclusion that is a fallacy. The reason we exercise is to turbocharge our metabolism, increase our insulin sensitivity and create a energy deficit so that when we do eat, the dietary fuels are used for recharging rather than just causing ups and downs in our blood sugars.

So, what is my point. A good way of dealing with exercise is to eat before exercise and bolus appropriately. And by appropriately, I mean that you may find that you need much less of a bolus to cover your carbs. Some people actually find that the increased insulin sensitivity during exercise means they can eat (some) without bolus. And you should try to start exercise with a minimum amount of insulin needed. So try to start your exercise with a “normal” blood sugar (not hypo) and having eaten (and bolused) and with your blood sugar rising (from eating). Sheri Colberg has very good advice on strategies for eating in support of exercise in her book "Diabetic Athlete’s Handbook."

And I would recommend that during exercise, you be prepared to support normal blood sugars by ingesting measured amounts of carbs during extended exercise. Bernstein recommends the use of small amounts of glucose at measured intervals (I like smartie tabs)

ps. And higher blood sugars are not good for exercise, they impair your performance and once you get over 250 mg/dl you start to risk creating the conditions that lead to DKA.

I’ll start out by confessing that I haven’t rigorously exercised regularly in several years, but when I did (playing Ice Hockey) I was always best off going into the exercise with a BG of about 140 - perhaps higher if I had some insulin on-board from a recent meal. If my blood sugar is high (200+), my muscles would ache and I would become winded much faster than if my BG was lower.

I have heard that it’s not good to exercise if your BG is high. I’m not sure why, but if I try to fabricate a reason in my mind (disclaimer: this might be 100% wrong) I’d guess that it’s because you simply don’t have enough insulin in your body. Remember that insulin allows glucose to get from the bloodstream into the cells, it doesn’t just lower BG. So if you’re exercising, have lots of sugar in your blood, but run out of insulin and can’t give that energy to your muscles that need it, you become fatigued and could go into DKA. Again, could be completely wrong.

A high-protein or a high-fat (I know, that seems to contradict the whole point of exercise) meal may be a good idea for you, to try to sustain your levels during exercise. Immediately - and for several hours afterwards - take less insulin or eat more low-fat carbs to keep yourself in control.

Another side note: I’ve tried bringing my meter with me to the players bench at the hockey rink, but it was too cold and would never work. Sigh.

I’m T1 and very active. For me it depends on the kind of exercise that I’m engaging in. Going out for a long run (something slow and steady that burns a lot of calories) will always make me go low, regardless of what my BG is when I start. Generally, I just try to start exercising with something above 115 and then I consume some Gu, glucose tabs, or juice about halfway through. HOWEVER, if I’m engaging in any exercise that results in any kind of adreneline rush (such as running in a race or anything that involves sprinting), my BGs will always go UP. For those types of exercise, I have to bolus 0.5 to 1.5 units BEFORE I begin my activity. This will ensure that my BG stays down under 160.

I’ve bolused during runs a couple of times, when my BG got out of whack. I am sort of addicted to running when it’s nice out, as the weather has been pretty foul a lot this year, and if I get a nice day and a window of time, I’m going to work around my BG. Most of the time, I’ll bolus for about 50% of some carbs and it works nicely. Come to think of it, I did that yesterday and ran a PR @ 5 miles, finishing at 88, despite some 160s on the CGM a couple of miles into it.

Hi Rye,

Well, it really depends on the person. First, I guess I should ask, are you ONLY on lantus? Have you passed your honeymoon stage? Personally id depends on what time I do my exercise. If I do mine in the morning a little after I wake up, I know that I have no active bolus insulin, so I normally don’t need my glucose to be that high. .However, having an insulin pump really helps me to make these kinds of decisions; it’s a little more tricky when your on MDI (speaking for myself).

Now, the other issue is “Exercising is not good with high BG’s because in the long run it can make you gain weight”. This statement is not entirely accurate. First off, the very act of exercising will raise your blood sugar. So should people no longer exercise? It’s actually a combination of many things that contribute to weight gain.

If excess blood sugars are consistently high, our insulin stores some of that sugar as fat. Also, keep in mind that, sometimes our bodies don’t use the insulin right away, sometimes the body does not use insulin until hours later. Talk to your doctor and find out what your target blood sugars should be before exercise. Maybe in your case it should be a little less.


Do you manage to test on the fly, or do you stop? You must stop, right?

Hi -

Just curious - how low do you end up if you start at 180? To have to be high enough to spill sugar urine before exercising doesn’t sound optimal.



I admit I do not know exactly how many carbs I eat, I SWAG too much…lol…But everytime I do my meals with a CDE or my endo they notice I eat well below the recommended carb intake. It was a diet plan I started years before I was a diabetic to help me maintain healthy weight and I have a small case of adult ADD so I dont really keep up with numbers…lol

Recently I was staying with my family and they noticed I didnt eat enough protein so I now I make it a point to eat more but I had not tried it before a workout. I am def going to try that

Thanks bsc, I will look those links up!