Spikes when exercising

Found this thread whilst trawling looking for info on exactly the same phenomenon as @sw600 describes in the OP. I'm a keen, competitive, orienteer, with a similar health backgrouns to sw600: prediabetic for around 5 years, A1c in low 40s. In my first race since wearing a Libre had exactly the same thing happen to me, with the highest BG reading I've yet had of around 12, peaking half an hour into the race where I was running between midday and 1 (see screenshot). This was after I'd had my regular pre-race breakfast of porridge and berries in an otherwise low (not keto) diet, which is what caused the earlier spike (which actually measured at 10.4 - the graph line doesn't always match the individual recordings, and I'd be interested to know why - presumably some sort of smoothing?).
This thread is some sort of comfort - not alone! - but it seems to me that the pre-race carbs suggestion is not the solution, if a solution is needed, ie this is a normal phenomenon???
Incidentally, my training runs earlier in the week, one purely a recovery session the other fartlek, and the single gym session, had no impact whatsoever on BG levels.
On a slightly divergent note, it does seem that the strongest reaction I get so far is with porridge. Tried it a couple of different ways since starting the Libre, and both times it's sent my levels into double figures. Even bread, rice and scone (all experimental!) have all only hit the 8s and low 9s.

velofan said:

In my first race since wearing a Libre had exactly the same thing happen to me, with the highest BG reading I've yet had of around 12, peaking half an hour into the race where I was running between midday and 1 (see screenshot). This was after I'd had my regular pre-race breakfast of porridge and berries in an otherwise low (not keto) diet, which is what caused the earlier spike (which actually measured at 10.4 - the graph line doesn't always match the individual recordings, and I'd be interested to know why - presumably some sort of smoothing?).
This thread is some sort of comfort - not alone! - but it seems to me that the pre-race carbs suggestion is not the solution, if a solution is needed, ie this is a normal phenomenon???
Incidentally, my training runs earlier in the week, one purely a recovery session the other fartlek, and the single gym session, had no impact whatsoever on BG levels.

Click to expand...

Nerves/stress perhaps in this case then, which I guess are going to unavoidable until a given race is either very familiar or unimportant - I get this from long rides to places I've not been/longer distances than I've ridden before.

velofan said:

On a slightly divergent note, it does seem that the strongest reaction I get so far is with porridge. Tried it a couple of different ways since starting the Libre, and both times it's sent my levels into double figures. Even bread, rice and scone (all experimental!) have all only hit the 8s and low 9s.

Click to expand...

There does seem to be a general trend with people reporting that porridge does this. I find it raises my blood sugar quite quickly, but I've nothing to compare it against really (and it gets somewhat lost in the noise of dawn phenomenon and the effect of whatever I'm then doing first thing) and I actually only eat it for the cholesterol lowering effects. What type of porridge is it? Mine is flat rolled jumbo oat, or something along those lines, and depending on how long it stays in the microwave (if I'm too high to eat, vs I just need to get out the door) it can have varying consistency - I wonder if this has an effect, not sure the effort of logging porridge consistency is going to be that much fun though (but I do prefer it a bit crunchy!)

SimonP78 said:

Nerves/stress perhaps in this case then, which I guess are going to unavoidable until a given race is either very familiar or unimportant - I get this from long rides to places I've not been/longer distances than I've ridden before.

Click to expand...

I race quite regularly (orienteering is like that, as you almost need to race to get decent technique training), and this wasn't an important one, so very relaxed. But I was racing, so pushing hard mentally and physically whilst out there. I put it down to adrenaline effect.

SimonP78 said:

There does seem to be a general trend with people reporting that porridge does this. I find it raises my blood sugar quite quickly, but I've nothing to compare it against really (and it gets somewhat lost in the noise of dawn phenomenon and the effect of whatever I'm then doing first thing) and I actually only eat it for the cholesterol lowering effects. What type of porridge is it? Mine is flat rolled jumbo oat, or something along those lines, and depending on how long it stays in the microwave (if I'm too high to eat, vs I just need to get out the door) it can have varying consistency - I wonder if this has an effect, not sure the effort of logging porridge consistency is going to be that much fun though (but I do prefer it a bit crunchy!)

Click to expand...

I've tried both pinhead (or steel cut) and rolled jumbo. No difference. I cook over a stove, preferring it well cooked but slightly runny. Make a portion with 65g of oats, water and 150ml of semi-skimmed milk - which probably contributes, but I find porridge inedible made with water alone - accompanied by 100g of berries.

velofan said:

I race quite regularly (orienteering is like that, as you almost need to race to get decent technique training), and this wasn't an important one. But I was racing, so pushing hard mentally and physically. I put it down to adrenaline effect.

I've tried both pinhead (or steel cut) and rolled jumbo. No difference. I cook over a stove, preferring it well cooked but slightly runny. Make a portion with 65g of oats, water and 150ml of semi-skimmed milk which probably contributes, but I find porridge inedible made with water alone, accompanied by 100g of berries.

Click to expand...

It doesn't matter what type of porridge it is, diabetics shouldn't eat it, full stop

Rockin'55 said:

It doesn't matter what type of porridge it is, diabetics shouldn't eat it, full stop

Click to expand...

While most diabetics will rise from porridge, not all do.
Many T1's would be able to dose for it, and there all also many T2's on a fixed insulin regime or gliclazide based on having an amount of carbs with each meal.
If they would suddenly swich to low carb they would end up dangerously low.

There are also those who swiched from sugary cereal to porridge, which is a great improvement and it might be enough for some.

Not one size fits all with diabetics.

Rockin'55 said:

It doesn't matter what type of porridge it is, diabetics shouldn't eat it, full stop

Click to expand...

I know one T2 who gets a very low response - porridge is not a problem for her. But,sadly, it looks like you're right when it comes to non-diabetic me; I'll have to rethink race days!

On gym days I find 3 scrambled eggs on a small slice of wholemeal toast enables me to lift heavier& doesn’t cause a spike, I have a protein shake with almond milk about 30 minutes later
On non gym days I find a couple of eggs (boiled, scrambled, fried) followed by chia seed pudding & blueberries has minimal effect on my blood sugar

Like you, I find eggs invaluable. I also find I can do most of my training on low carb, higher protein/fat. However, racing longer distances (for me over 40, up to 80 mins) makes a carb input important. I was racing again this weekend, and tried 2 boiled eggs and a small slice of sourdough wholemeal for breakfast, which doesn't spike for me. Energy fine for first half of 80 minute race, but did needed carb supplementation (jellybabies!) for second half. By that stage, blood sugar had already higher levels (c.10), and flatlined for rest of race. As soon as I finished, the sugar levels dropped to normal. Perhaps body needs higher levels - as transporting to muscles? I just haven't been able to find anything yet to confirm or otherwise.

Morning DP and swim spike even with insulin. A pain in the neck.

Hi people - I just want to add here that its not only the exercise that spikes me. it depends on the exercise and the stress level for me. So when i exercise sometimes it goes up sometimes just down - depending on how hard i am working, but also I spike through the roof - up to 13 when playing chess. I get really stressed when playing league games - No extra food, but during a 5 hr game my levels can go all over the place. I was totally confused to begin with but apparently the fight or flee response and stress, adrenaline etc. causes a big release of glucose...