Going low when exercising

Type 1 and LADA
21

Exercising right after a meal and bolus is tough. Have you considered doing your walk before you eat?

If you think about athletic competitions, nobody eats right before the event, even non-D’s don’t do that.

Eating 2 hours before exercise is usually the ideal time-frame for a hard effort that needs perfecting fuel (such as a competition).

And eating either 4 hours before the exercise or right after the exercise is good for less intense efforts.

If you eat and bolus right before exercise it is doable, but it just needs close monitoring and corrections.

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22

I don’t think that would work because I walk during the morning so if I had to exercise before having breakfast I’m not sure I can sustain the session on an empty stomach. And I’ll feel miserable exercising hungry.:sweat_smile:

This have the bolus seemed to work for me last week, this week I seem to have a different result. Perhaps my timing is off. My exercise isn’t intense, just about an hour of fast walking.

I also like the idea of bolusing less because I will exercise after a meal.

Should I be already into the walk and getting a fast pulse by the first hour or is it the time I leave the house for my walk in order to stop my BG climbing to the top?

23

This will be trial and error too because everyone is different. I would think you want to intercept that blood sugar from going high from the lower bolus. On a Dexcom you’ll see blood sugar starting to rise about 20 minutes after a meal so you’ll want to head that off at the pass. Prebolus timing also comes into play, so that is another factor to adjust. Unfortunately there’s no easy answer you have to just see what works for you most of the time.

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24

I’ve been reducing my bolus and finding the sweet spot for the reduction amount. At the moment its about 40-60% and its frustrating that what works on one day does seem to have the same results on another despite having the same breakfast. I guess that’s the unpredictability that comes with D.

Just want to get some opinion on something. After my walk today and yesterday, I came in nicely at 4.6mmol (~80mg), had 3 small chocolate drops and did another 30 mins of aerobic exercise. I was feeling good at the end of the session - no hypo or hyper symptoms. Jumped in the shower and 45mins after measured my BG and it was 8.6mmol (155mg) which was higher than what I was expecting given my 30 min additional aerobic exercise was low impact high intensity and I was sweating by the end of it. I would have liked it to be sitting under 6mmol (100mg). But it went up.

So where did I go wrong? What had caused the increase in BG.

  1. Is my basal setting not strong enough for the window an hour before my BG measurement, I didn’t suspend my basal at all.

  2. Did I not reduce my bolus enough? The fact I came in after my initial walk at 4.6mmol (80mg) suggests that this was a good amount.

  3. Or was it the chocolate I had? I was afraid I would hypo if I didn’t get my sugar up before my aerobic. The amount of chocolate I had was so small I didn’t think this was a factor. I had 3 of these (not packets :smiley:, actual chocolate!)
    https://www.lindt.com.au/shop/fruit-and-crispy-sensation/fruit-sensation-raspberry-cranberry

25

It does depend how many carbs you consume for a low. 2 carbs from a vegan gummy bear makes me go up about 10 points. But it can make me go up 15 sometimes. There is a delayed reaction to going up to the full amount too. Chocolate has fat which would delay some of the absorption. So you probably need to look at how many carbs are in what you ate.

Hot showers send me though the roof fast. The earlier I take them the more it sends my BG up. I try to take lukewarm showers in the evening so it doesn’t effect my BG level as much. I actually don’t feel well from a hot shower that’s more than a few minutes because my BG wants to climb so fast.

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26

For me exercise will absolutely weaponize any insulin on board and send my BS crashing. I work out in the morning on an empty stomach. I spin and weight train and do not have to make any adjustments.

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27

I just had a look at the packet, it’s 15g per serving and there are 6 servings in a pack. So I would guess I only had like 2g of carbs which in my mind is immaterial to make any difference.

Isn’t hot showers supposed to bring down BG not the other way around? My body usually reacts to it this way. My shower wasn’t hot anyhow and I was in and out quite quickly.

It just seemed that my exercise was able to bring down my rising BG but not long enough to sustain it from rising again.

28

@tedos
Hot showers makes my Bg increase but most I think it makes it decrease. I agree 2 carbs should not have raised it that much. If your second workout was intense then maybe it was that that made it increase.

Riding my exercise bike I decrease my BG levels, but lately snorkeling is causing my Bg levels to increase after I have stopped.

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29

Interesting- could be, it was mostly cardio. Everytime I do it I am hoping it decreases my BG but it either sits steady or goes up. Is it known that intense exercise end up with a high BG? I’ve never heard of that association before.
I always thought the harder you work the quicker your BG drops.:sweat_smile: Like why would i work so hard if it has the reverse effect :thinking:

30

Hard exercise will progressively make a bigger impact on your BG. The harder you are exercising, the more it will drop you UP TO A POINT.

But once you get close to your threshold effort - the point at which the concentration of lactate begins to increase exponentially because it is being produced much faster than it can be broken down and reused - you will see a BG rise because your body will release epinephrine and cortisol.

Epinephrine and cortisol affect your BG in 2 ways - by causing glucose to be released and also causing insulin resistance.

The threshold point varies with your fitness level, but a general rule for it is when you get to about 75-80% of your maximum oxygen uptake, you are near that point.

And it can also vary with duration. For example, an hour at 70% might get you there, or 15 minutes at 90%.

This is a very short explanation. If you want more details, let me know.

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31

@Eric2 You just explained something I didn’t know…It should have dawned on me. I have switched snorkeling from about an hour each time (and that always just dropped my Bg levels,) to a newer technique of eating about 15-30 carbs before I go in, having a Libre to scan out there and staying out until I am tired or I have to head in instead of wondering about my Bg level and coming in after a certain predetermined safe time (an hour before with reducing basal). So I am snorkeling and swimming 2-3 hours. And have only been stopping when I have been tired!

But my Bg level has been climbing after, this I knew and expected about because I am swimming a lot in ocean currents and really working at it. But it is taking a lot of insulin to bring down my Bg level after and hours of stubbornness to do so. I watch it climb take some insulin and an hour later I am still climbing.

I didn’t realize it can cause insulin resistance after and I’m sure that is what’s going on! Thank you!

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32

The info below probably does not apply to snorkeling because you are probably not eating while snorkeling (that would be tough to do :joy:), but related to all of this - another thing that might be a factor during other types of exercise is when someone is taking in carbs WHILE they are exercising.

Those carbs may not be absorbed completely until after a person finishes.

When your body is trying to prioritize blood flow to exercising muscle and lungs, digestion is somewhat put on the back-burner. Your digestion is slowed down.

Furthermore, when you become dehydrated, like you might experience during exercise, your digestion is slowed down.

Once you stop exercising, you rehydrate and your body starts to reprioritize digestion, so the rest of the carbs you consumed during the exercise will finally start to kick in.

There are a million references available for this concept, but here is one:

Exercise and digestion can be mutually exclusive. When you exercise, your body isn’t using its energy for digestion. Instead, it slows any digestion currently taking place so it can divert as much blood as it can to feed your muscles and your lungs.
How Exercise Affects Your Digestion - Manhattan Gastroenterology

So in short, if you are taking in carbs during intense exercise, some of the carbs may not be fully absorbed until after you finish. It also depends on the type of carbs. Liquids are fastest during exercise, followed by gels.

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33

@Eric No…lol…not eating while snorkeling, Although I carry crystallized ginger candy with me just in case! But not hydrating either. I am used to drinking tea or water constantly and that might be adding to the problem. It’s well worth it though so the trick is trying to figure out the solution and not doing any rage bolusing because that ends badly. :grinning:

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34

Great explanation!

So it may not be my dosage that’s incorrect (although I can’t really rule this out). Any suggestions on what I can do to prevent my sugar spiking after I exercise? Should I be increasing my temp basal to 130% when I start exercising so by the end of the hour session it would have start kicking in?

I find this a bit counter intuitive, here I am trying to lose weight by reducing the amount of insulin I need (Via reduced boils) but feeding it another way (via basal) :exploding_head:

I find that it’s usually when my body starts calming down for a while that the BG starts climbing. So after my shower and resting a bit.

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35

Depending on what your BG is, if you can take a bolus a a little before you finish, or right when you finish, you can prevent the spike.

A higher basal can also prevent a spike, but I just find boluses to be much more powerful for preventing spikes - as long as you know a spike is predictable.

Like as an example (depending on your basal rates) if you compare a 3 unit bolus versus a 130% basal increase - it might take 2 hours of temp basal to make up that 3 units, compared to the 3 unit bolus you can take all at once.

I guess it just depends on your preference. But I always take insulin AND carbs right after a workout, and I do it with a bolus. That is how you get the glycogen back into your muscles for the next day’s workout.

Do you eat any carbs while exercising? And are you T1 or T2, and how long have you been diagnosed? Do you have any glucagon response still?

A spike a short time after exercise can be caused by many different things.

For some people it is the fact that have been running on a zero basal for an hour or two, and after they stop, they have no insulin left in their system.
(I think you mentioned above you are on 0%, is that right?)

For that situation it might help to have a small basal still running during exercise, like 20% or so (as long as you are not dropping too low).

For others, a spike might be because of a cortisol and epinephrine response as I mentioned previously. But going back to your initial post, if you are walking, I do not think those hormones are a factor. That would only be a factor at higher intensity.

For some, it is the carbs they ate during their exercise, and the carbs finally kick in when they stop. But again, that is probably not at play if you are waking (Sorry, I should’ve reviewed your initial post before writing all these things. Those are valid for higher intensity exercise, but probably not your situation.)

And for some, there can be a glucagon response. That depends on the type of diabetes you have and how long. Like it might be a factor for a T2 or a new T1, but probably not for a long-time T1.

So considering all of these possibilities and after re-reading your initial post, I would suggest trying either a small basal left on during exercise (somewhere like 20% or so), or a small bolus right at the end of exercise.

Or try them both (but not at the same time!!). Like try it both ways but on different days, and see which works better.

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36

Thanks so much

Oh my, I’m learning a lot today :grin:, I never do this!!! I feel bad eating after all the effort :weight_lifting_woman: working out - seems the workout is wasted if I eat :sweat_smile::woman_facepalming:t2:. However coincidently lunch is not far away so I would have food with in 1-2 hours of finishing my workout.

I never eat while exercising. Maybe if I’m going down I’ll have a candy to mitigate a hypo. I’m a t1 and have been for 20 years. No idea about the glucagon response . Don’t know what that is even after googling.:sweat_smile:

Initially i was, but it was recommended by others I reduce my bolus instead so now I just reduce the bolus and leave the basal running.

Haha that wouldn’t have helped much because since my initial post my exercise regime has changed a bit. So my situation is, I do a long walk (either 30 mins fast walking or one hour moderate). After my walk, I do some cardio or aerobic workout for 30 mins. It’s not super intense however it’s called “low impact high intensity” - but again not super intense on my opinion. My heart rate is probably about 140bps-150bps at the most intense part.

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37

Depending on what your resting heart rate is, being 140-150 might be enough to trigger the cortisol and epinephrine response that I mentioned before, and that would raise your BG. So considering that, I think that is a likely factor in what you are seeing.

If you bolus for the post-workout rise just enough to cover it and bring it back down without needing to eat anything, then the weight loss will not be affected. You can just test out amounts until you get it right. 1 unit? 2 units? 3 units? You can get it dialed in with practice. And I would suggest doing it right after your workout finishes.

Keep in mind though, if you keep doing the same workout for weeks or months, eventually you will not have the same BG rise. Your body will grow accustomed to it and it will not effect you in the same way.

That is a training adaptation, and that is a good sign!

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38

Thanks @Eric2 makes sense.

Yeah I’m noticing this already. Trying to figure this all out with so many changing variables is quite challenging. By the time I work out what is working, something changes.

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39

Yesterday I went for a 1.5 mile run over moderate terrain. I started around 5:50 pm at 130 mg/dL and by the end of the run I was down to 58. I hadn’t taken bolus insulin since lunch 5 hours earlier and my basal is only at 3 units a day. This is the first time I’ve dropped so rapidly in such a short time frame. Makes me worry about taking longer runs.

40

Is your body still making some insulin? And are you on injections or a pump?

What are you doing for carbs when you run? I like Huma gels and Transcend gels and the Gatorade Endurance gels. Transcends are 15 grams, and the Huma and Gatorade are around 20 grams.

If that is too much, there are also the sports jelly beans, but they are not as fast.

It just takes practice to get it all dialed in. If you are on a pump, turning your basal down can help. If you are doing injections, you will need to take some carbs along for the longer runs to cover the basal.

Your body will use all its fuel sources, but the fastest fuel source it has access to is the sugar in your blood. That is instant, it will pull that right away, so it is normal to see a drop in the first few miles (which is why it helps to have some gels with you). It will also use your muscle glycogen and your lipids (which will not drop your BG), in addition to the carbs you eat.

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