Type 1 Exercise question

[ElyDave]

Very interesting experience today during my afternoon run. An easy 10km, with testing every 5km.

Lunch was at 12:30, approx 75g carbs, 5 units Novorapid. Run at 3:30pm
Before 7.3
at the 5km point 3.0
20g carbs
at end 5.1

Two things there of interest to me
1) in theory with three hours from meal to run, I should not have had to reduce my dosage according to usual guidelines
2) at 3.0 I had no "hypo" symptoms, I had heavier breathing and sweating from the running, slight light headedness, but it was a cold day and I always get that kind of a sensation whether running or on the bike.

This is the second time I've had something similar, on the bike last weekend, forgot to eat early enough and when I tested at my usual 45 mins, I'd gone from 9.0 to 4.2, at which point I was starting to feel it a bit, but that could also have been the hill I'd just cycled up.

Anyone else get any masking of symptoms during exercise?

 

[hale710]

No, but that's my fear. As soon as I feel myself getting really pushed I panic that it's hypo and not just me getting out of breathe etc. so far I've never gone hypo during exercise though lol


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[mrman]

Tricky one this in it lol. I find that even 3 hours after food I need at about 50% less bolus to avoid a hypo, even with being able to put a reduced temp basal on. Though, if I were to do this would result in a high reading after 2 hours, probably over 13mmol which is then advised to not exercise, as quick drops from that level can have effects, as well as the risk of then not having enough insulin working leading to higher levels.
I now exercise within 30~40 mins of a reduced bolus before planned activity or sip on lucozade just before and during exercise if after 3~4 hours of meal/bolus. Other option is to have a carby snack big enough to avoid a hypo.


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[Miklo]

Very interesting experience today during my afternoon run. An easy 10km, with testing every 5km.

Lunch was at 12:30, approx 75g carbs, 5 units Novorapid. Run at 3:30pm
Before 7.3
at the 5km point 3.0
20g carbs
at end 5.1

Two things there of interest to me
1) in theory with three hours from meal to run, I should not have had to reduce my dosage according to usual guidelines
2) at 3.0 I had no "hypo" symptoms, I had heavier breathing and sweating from the running, slight light headedness, but it was a cold day and I always get that kind of a sensation whether running or on the bike.

This is the second time I've had something similar, on the bike last weekend, forgot to eat early enough and when I tested at my usual 45 mins, I'd gone from 9.0 to 4.2, at which point I was starting to feel it a bit, but that could also have been the hill I'd just cycled up.

Anyone else get any masking of symptoms during exercise?

Looking at what you said everything is based on excellent figures with respect to test results carbs eaten and timing but for me there is very little room for a margin of safety.

When doing a 10k I would not feel comfortable with what you have said I would have dropped my doseage to such before my run a test would have been a 10 before setting off aiming to arrive back with a 6-7 result. the running club where I went to made no allowances for diabetics and would have been left walking home hence I used to go in slightly high and always had a bottle of lucozade sport in 1 hand especially on a half marathon trainging night with glucosse tablets in my pocket just in case. All my runs for the past 15 years commence on a static reading of between 8-10 with this I mean most fast acting as insulin is depleted. my readings are never high when I get back but there is nothing worse than a low blood sugar start on a competitive run.

 

[ElyDave]

Miklo,

thanks for your input and experience. TO be honest I ran today closer to a meal than I usualy would but I wanted to get home before it went dark.

Normally I look to start running at >5.5 for an easy/steady run of 10km or less as long I have 4 hours after the meal. If less than 5.5 I'd take a quick snack of 10-15g carbs. My aim is to get home at 4.5-5.5.

I'd definitely look to be higher during a 10k race, where I'm going harder, have no chance to eat and no chance to stop and test. MY new Year's Eve 10k I started the warm up at 11.5, and the race at 9.3. Finished at 7.8, but there was a lot of adrenaline going on that day.

I shall have to think about dose reductions for anything up to 4 hours by the looks of it.

I guess I'm just lucky in that my cycling club are happy enough to let me try and make a gap every 45 mins to go and test and then wait for me to catch up again.

 

[phoenix]

Yes, it was when I got off my bike, tested for lunch and registered 'lo' that I got scared, On that occasion I felt fine . At other times I would feel fine but then very suddenly feel low and realise that I needed glucose to carry on. I was often in the low twos and came to a full stop. I tried not to exercise within 2 hours of a meal but it still happened.
Lows during exercise were what made my doc suggest a pump. It helped but even using a pump with a tiny basal, didn't eliminate the problem
It's got easier recently and it doesn't happen so frequently. why?
Probably don't exercise so much; so less insulin sensitive..
Maybe, I have a bit less of my own insulin(?)
I take small amounts of glucose (1 dextose tab) frequently during exercise, especially before extra exertion (ie in my case before hills). Often I don't even test before I take it.
I'm not so worried about a higher reading before exercise and reduce pre meal bolus when possible, in my experience, glucose levels have on every occasion bar one come down during exercise (the one time it rose was when I fell badly about 3 miles from home) . I'm rarely above 10 or 11 though.
I had an HbA1c of 4.9% pre pump. it's about a percentage point higher now, so higher than a non diabetic, but has been stable for 5 years and I'm happy with that.
.

 

[Miklo]

ElyDave

You seem to have it down to perfection and I have a lot to learn with respect to your results, I always struggled with clubs with many sports as I hate running high at the start of any session for one the constant tripping to loo prior to start time especially if delayed and even worse if it is a light session. Plus a lot of clubs have somne weid start times either just after tea or work which leaves you the question do you eat before or after.

 

[sheil19]

Often happens to me after an intense 35 mins run, I seem to go hypo!! Doctor recently gave me a tip that has been working....after I finish my run I do a 100 metre sprint and it releases adrenaline which raises my BG level and gives me time to get a shower and then eat after. Works for me, so maybe give it a try and see how you go!!


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[ElyDave]

I've heard that one as well Sheil, will have to remember that.

Miklo, I think we're all learning from this, it's just what works for us individually.

Thanks Phoenix, helpful as always

 

[ElyDave]

So, the experiment continues.

Sunday 10km 3 hrs after novorapid, Before run 7.3, mid point 3.0 took 20g carbs, end 5.1

Tuesday morning, before breakfast, no novorapid, no morning basal, 8km - pre 5.3, post 5.6 - no effective change

Today - 10km approx 5 hrs after lunch, so no QA in my system - pre 5.9, mid 6.0, post 4.2.

This time in the last km I was definitely feeling a bit fuzzy headed, but interesting that all the drop came in the last 5km.

 

[mo1905]

It appears your experimentation is bearing dividends Dave. Those figures seem pretty good ( OK, not the fuzzy head bit ). As for not noticing a hypo mid-run, I'd have thought many of the signs/symptoms for a hypo and heavy exercise are very similar so very difficult to pick up on.

 

[ElyDave]

It appears your experimentation is bearing dividends Dave. Those figures seem pretty good ( OK, not the fuzzy head bit ). As for not noticing a hypo mid-run, I'd have thought many of the signs/symptoms for a hypo and heavy exercise are very similar so very difficult to pick up on.

that's the problem Mo, the 3.0 on Sunday I did not feel at all.

This is partly why I think the pump would be helpful for me, gives me the ability to carry minimum insulin on board and clear it out of my system before a run.

 

[mo1905]

that's the problem Mo, the 3.0 on Sunday I did not feel at all.

This is partly why I think the pump would be helpful for me, gives me the ability to carry minimum insulin on board and clear it out of my system before a run.

My point is though Dave, it would be very difficult to spot a hypo during intense activity anyway as signs/symptoms are very similar. Also, you run your BG levels very low anyway which also doesn't help. You start to get used to running low and you start to lose your hypo awareness.

 

[ElyDave]

Mo,

very simple equation

Insulin causes hypos

No insulin = no hypos.

I do feel the lows, this week I've been running around 5.5-6.5, hardly low. I've only had a few reading lower than 4.5. The problem as you point out is that all hypo symptoms are very typically exercise symptoms as well.

 

[mo1905]

OK, I thought you were having trouble feeling hypo's ? your previous post mentioned not feeling a hypo at 3 ?

 

[hale710]

But Dave you would still have insulin with a pump? You could put a tbr and reduce it sure, but you will still need some insulin on board


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[phoenix]

But Dave you would still have insulin with a pump? You could put a tbr and reduce it sure, but you will still need some insulin on board


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I find this one difficult. To stop the pump or do as I do use the tiniest possible basal.
The only time I stop insulin entirely is swimming and that can still make my levels drop like a stone in a very short time. What we can't get rid of is the insulin already infused. Normal peoples insulin has a really short half life, injected insulin lasts for much longer and with a pump you may also have an unused depot in subcutaneous depot.

 

[ElyDave]

I find this one difficult. To stop the pump or do as I do use the tiniest possible basal.
The only time I stop insulin entirely is swimming and that can still make my levels drop like a stone in a very short time. What we can't get rid of is the insulin already infused. Normal peoples insulin has a really short half life, injected insulin lasts for much longer and with a pump you may also have an unused depot in subcutaneous depot.

Yes, but I'm guessing it wil give me a better chance than an injection.

I'm going to talk to one of the DSNs about dropping my bolus all together on long run/ride days - try to go fat burning.

 

[ElyDave]

even more fun and games today, trialling a new mountain bike.

Consulting TLAP gave me a factor of 0.33 for 2 hours of high intensity work. Lunch was 60g of carbs which gave me 4 x 0.33 units, rounded to 1.5.
BG before was 6.1, an hour later setting out to drive, it was 6.7, which was very unexpected for that much carbs with that little dose. A quick 10g carb additional snack adn still only 7.8 when I started my ride half an hour later. Testing every half hour it went like this.

Time 0 - 7.8
30 mins - 5.8, 30g carbs
60 mins - 5.3, 15g carbs
90 mins - 5.5, 30g carbs
100min finished ride
30 mins later, at home - 6.9, no carbs
45 mins later, after washing me and the bike 9.0
8pm at dinner time, 5.7

Overall more good information, but slightly puzzled by the pre exercise readings on that little insulin. Lunch was toast, poached eggs, smoked mackarel and an apple, so some protein and fat to slow release.

And the new bike, excellent.

 

[hale710]

Honeymoon explain the lower start? If I allow my pancreas to work it can do some amazing things sometimes (or it used to!)

And what is tlap?


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