How does regular exercise improve control?

So after reading through the discussion here…

Habits of a Great A1c: Carbohydrate Intake:

I can’t ignore that another tenet of well managed diabetes is regular exercise. It’s discussed so frequently, yet I can’t understand it. Occasionally I hear a few others who find exercise difficult to implement because of diabetes. It makes me wonder if there’s simply a matter of correlation over causation.
Now I love getting regular exercise (which is part of why this is so frustrating). I could go on and on about how much I love it… It’s just that it creates a disaster(a manageable one) as far as blood-glucose levels go (like eating my weight in pizza).
So before I keep ranting and start with my own hair-brained theories about it…
How does exercise improve your control? IF that’s even the right question…

Exercising greatly increases a persons insulin sensitivity in the hours following a workout. If you are still producing insulin, it helps you utilize it better. If you produce no insulin, it will decrease your exogenous needs somewhat.

What Rwaz just said!

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On every cell there are whats called telomeres. Everytime a cell replicates it loses a telomere. When all the telomeres are gone from a cell line they die off, forever. Exercise adds telomeres to cells and is the only thing that can. In short, excercise prolongs life. Additionally muscle cells don’t need insulin for uptake of glucose and can take glycogen for energy uptake, using muslce decreases insulin resistance. However: excercise initially can also throw your bg out thanks to cortisol and co. So it can be difficult until you get into a routine.

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I don’t make any of my own insulin, but I use less insulin when I exercise plus it makes me feel good. I also do it because it helps control my blood pressure and keeps my LDL lower.

I sometimes have to eat fruit before I exercise, because exercise lowers my glucose levels a lot.

Type 1 dx in 1959.

I would love to learn how…or how long it takes to regulate…
When I do strenuous work my blood sugar numbers soar upwards to 50 or 70 above my norm of average 90.
I am beyond frustrated trying to learn how to do the insulin … how to monitor…no pump just MDI.
I may be hijacking the intent of this thread…I welcome a person willing to mentor me thru private convos.
And the tele thingys …heard of them but didn’t know about the life extension.
I learn so dang much hear…

Exercise is a learning curve as a type 1. And it can be so different for each of us and how we respond. I ride my exercise bike at least 10 miles everyday.

When my BG is shooting up faster and more than I expect it to, maybe because of timing or having to guess at dosing. It seems to halt the climb within 10 points when I get on my bike. This starts to happen pretty quickly. It also helps bring down my BG level faster than just waiting for insulin to kick in.

But the trick? Up to 20 minutes stalls the rise, but more than that can make my BG drop. So sometimes I am purposely only getting on it for a shorter time. And sometimes I don’t make it to 10 miles and try again later or I have to eat something to keep going. If it’s planned I don’t always dose as much and try to get on after a meal.

More intense exercise like snorkeling, I reduce my basal a half hour before for about two hours. And most of the time I make sure I eat something within about an hour afterwards.

I had read somewhere, and it seems to work for me, that reducing insulin while exercising is better than suspending it to stop an increase in Bg’s after.

The reason you see a rise from your strenuous exercise is because anaerobic exercise raises BG temporarily since your body figures you are fighting or working really hard it will give you a blast of glucose for energy which we diabetics can’t use very well. If you keep on exercising at the same rate you will eventually start dropping unless you 1. Eat food to sustain yourself or
2. Drastically lower you basal rate for those on a pump.

The best kind of exercise for lowering BG without first spiking is aerobic like walking, riding a bike or swimming. I find that these sort of exercises will make me much more insulin sensitive so if my BG is higher than I’d like it to be before I go out to do my chores (which are a mixture of aerobic and anaerobic) and I need to take some insulin first I will need to take that into account since it will work much faster than if I took it and sat around.

Exercise can make good BG control more complicated but for most people just taking a walk after a meal or when BG is higher than you’d like is usually a pretty simple trick to better BG’s.


thanks everyone!
At the risk of outing myself as completely dense… is it simply a matter of using the increased insulin sensitivity to your advantage? Less insulin, smaller numbers, so on?

It’s still abstract as I don’t see this translating to improved control (lower A1c’s). Rather it necessitates more aggressive management whether it initially brings you down or up like @NatureOrbs.

The survey results revealed that those with lower self-reported A1c levels were more likely to report exercising at least 4 times per week as compared to those with higher A1c levels among those with type 1 diabetes. Those with a higher A1c level were significantly more likely to report very low exercise frequencies (less than once per week). There were no significant differences in the proportion of people who reported exercising 1-3 times per week between the two A1c groups.

Now I can grasp that regular exercise is better than irregular exercise. The first 2-3 weeks of any exercise routine marks a time of chaos. Trial and error for specific activities has taught me to cut my TDD by up to 70% and also add lots of extra carbs. It’s difficult to track the curve, but that mire has been cleared it gets a little easier as long as it’s “routine”. Beyond that, I still get frequent days where with the same level of exercise, I can’t predict how my insulin sensitivity will change. With progression in mind, there are days where I might push myself much harder, and my IS will take an unexpected path.

Is there a discussion on the type of exercise conducted? I’m still shocked by the marathon runners group on Tud, as I find that type of activity the most difficult to manage. Are the proponents on the low A1c side of the study high-level athletes that skew the results?

So before I ramble any further…
What is it specifically that you think you’re doing right and what may others like myself be doing wrong? No time to be bashful. IOB, timing, activity type, fitness level, etc, lets hear it

finally @NatureOrbs, I’m not sure which questions to even be asking. Hijack away! I’m elated by the input.

Hello Oaks!
Well I will continue to dialog here about exercise and insulin.
I am going to first evaluate my questions for super clarity (as much as I can) and will post here tomorrow at the earliest…
:dancer: my favorite way to exercise btw.

Deep breath.


  1. We all have some variance so I imagine testing, testing and then more will be a part of the figuring out insulin dosage for exercise.

  2. Star position, moon waxing or waning may also influence results.

MDI only no pump or pump related responses please.

Example: The insulin I take impacts me 1.5 hours after injecting…meaning that’s when it corrects back to a “normal” blood sugar number.

Question: When is it advisable to take insulin for exercise? Before? Way ahead of time to match up with correction time?

             : Test every 15 minutes to start? 

Not addressing Aerobics or Anaerobic exercise this round. Unless of course it makes a difference when to bolus.


@oaks For me exercise means less insulin and faster results. If I see my BG going up, I can take a certain amount of insulin and wait for it to go down, if I get on the bike, I take less insulin, I get faster results. And I get the benefit of exercise which is good for me and makes me feel better.

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I am not a super exerciser but do love walking. I walk everyday and use it sometimes to help bring down a blood sugar that is a little higher than I’d like. Just a quick walk around the block.
That said, if you are into getting more from your exercise, may I suggest
They have a cool website that talks about all kinds of exercises. I also watched a documentary they did with a group of type 1’s who biked across the country. Very cool.