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Which kinds of exercise raise / lower blood sugar?

I've been in the sea 4 times this last week - very bracing sea temperature but otherwise warm and sunny. I have long covid, get tired and a raised heart rate v quickly so just had a dip, floated on my back and did some very gentle breast stroke for 25m. I was in for about 25 minutes each time and glucose measured by G7 CGM went from the 7's down to 4's instantaneously (i.e. first reading after entering the water) stayed down until about 30 minutes after getting out when it went back up to the 6's.
 
Sounds nice!

I don't know about the dexcom, but I've wondered if my libre readings are affected by fast changes in temperature, particularly in water. I often notice funny blips from a hot shower where the reading jumps up then down again to lower than the start.

The drop after is real (particularly if I've injected recently, as it speeds up absorption), and confirmed by finger tests, but not sure if the brief rise is actually happening in my blood or just an artefact of the sensor.
 
Sounds like a prompt for some (n=1) experiments in a Finnish sauna, with a roll in the snow afterwards.

Actually there may be an explanation. We have some special fat cells (adipose tissue) that arew specific for keeping certain parts of our core function working in cold weather (i.e. shivering) and so a sudden onset of cold hitting the body may trigger specific responses to burn lipid fat for a while in those tissues to maintain temperature. It is thermal shock after all.
 
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Oldvatr said:
As an adjunct to my previous post, i have not seen any scientific research on what the effect of sex has on blood sugar levels,
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I would imagine it would but without testing during or after I wouldn't know
 
Well I have just tested after a an hour of cycling and weights and mines up 7.7 However, give it a few hours and it should be lower again, in the 5s normally. I have been running higher the last few days due to the weather and too many cashews lol
 
Lainie71 said:
Well I have just tested after a an hour of cycling and weights and mines up 7.7 However, give it a few hours and it should be lower again, in the 5s normally. I have been running higher the last few days due to the weather and too many cashews lol
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~~I assume that is "up to" not "up by" 7.7
 
I'll check when I have a hot shower later.
 
This matches my experience so far as a T2. I did no exercise (or as close as I could get to none) before my diagnosis. Over the past couple of months I've been exercising more and have noticed it takes more now to raise my BG than at the start. To begin with, it spiked by 2+ points in the immediate sweaty aftermath. Now it's 0.5 at most (which could just be a meter error margin, admittedly), generally it barely moves unless I really push intensity.

I also generally see my BG level is noticably lower 2-3 hours after exercise than my pre-exercise reading, if I don't eat in between (i.e. lower that it would normally be without the exercise and not eating).
 
Personally I find my usual exercises of brisk walking, Pilates and Yoga all lower my blood sugar. If I do Pilates with weights that lowers my BG even faster.
I love to exercise but then have to top up with a bar or I'm down at 3.8 or lower. It's quite difficult to balance. ‍‍
I'm T1 on low amounts of insulin, I also weigh 42 kgs so that doesn't help.
 
I find that if I go for a walk 2 - 3 milestone my BG always drops and I need to eat to raise it. I'm exercising to try and get fitter and lose weight and I end up eating more!
 
Pat50D said:
I find that if I go for a walk 2 - 3 milestone my BG always drops and I need to eat to raise it. I'm exercising to try and get fitter and lose weight and I end up eating more!
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Do you have any flexibility on the timing of when you exercise?

I try to exercise so there's only an hour at most until my next meal when I finish exercising, or soon after so I'm still satisfied from the meal before. Doesn't always work out this well coordinated, but it helps when I can.
 
I ding with Nordic walking my bs initially rises and then falls. Reformer pilates, resistance training doesn’t affect it much.
 
Pat50D said:
I find that if I go for a walk 2 - 3 milestone my BG always drops and I need to eat to raise it. I'm exercising to try and get fitter and lose weight and I end up eating more!
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Why do you need to raise it? Are you seeing unusually low figures? Normally your liver will at least try to adjust your blood glucose itself as required.
 
I ride my bicycle at a leisurely pace along a nature preserve for about 8 miles and 40 minutes most days. I have found my reaction to my short term insulin is faster and less insulin goes further. And by BG is usually a lot lower when I get back. I actually had to start eating a small amount of steel oats before leaving to avoid hypos.
 
I took bloods at 8.04 this morning on getting up. 13.2. SHOCK HORROR!!!

Decided to do it again. Different finger different hand new test strip. 8.11am. 9. How is this possible. Is it normal?. Im depressed!!!!!

If bloods can change so much in such little time whats the point in checking them?
 
The meter is required to be accurate to within +/- 15% of reading. So this means that the difference between taking two meter readings even on the same drop of blood can vary (worst case) by 30% so it is possible that the two readings you saw are not actually what your blood sugar is doing, but simply due to the meter.

The other possibility is that one of test sites may have had some contamination - did you clean the sites before testing?

One other tip that may be valid - discard the first drop of blood and test the second one from the site. The interstitial fluid near the surface is significantly older than your current level, and this process clears it out and forces the test site to update to more recent level.
 
It has been likened to the measurement on a speedometer... what you are doing one minute may be very different the next. Each is just a snapshot at that point.
That's why it's important to take lots of measurements over time to build a picture.
If you see wide discrepancies between 2 readings in a short space of time, do a third, then a 4th say 15 or 30 minutes later. That will give better idea of trend or average. Libres (and other cgms) can be very useful too.
Just be aware if you are on meds that could make you go into DKA
 
This talk about rising or lowering BG only discusses affect immediately after (or during) exercise.
In my experience, all exercise will lower BG over the next 48 hours even if i see a rise during or after.
As well as cycling, I rock climb. This always causes a rise in BG (unless I adjust my insulin) but also causes an overnight low afterwards.
 
I have always been very physically active and find that exercise of any kind will dramatically lower my blood sugar levels. If I have a day where I am not anywhere near as active as normal then I have major problems with high blood sugar levels and need to have much more insulin and eat next to nothing. We are all different and we have to find out how different exercises affect us and then make informed decisions about what we do and how to manage the blood sugar levels.
 
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