Blood Glucose After Exercise

[Fencer]

Wow... Came home from the gym last night after quite an active workout and my BG was up at 9.2 mmol/l. I have not seen it at this level for quite some time. I often go to the gym, but have not really been testing afterwards... will do for the next few times to see if this is a one off or a trend.

Is this normal? Should I be concerned about it? I had not eated since midday when I had my lunch, went to the gym from 18:30 to 20:30 and tested at 21:00. I had a bottle of Lucozade 'light' during my workout, but wouldn't have imagined that did the damage.

 

[louiseb]

did you test before you went into the gym?

I know excercise usually brings your bg down, but there could have been any number of reasons for bg being a little higher, stress, coming down with a bug or the lucozde light might be the reason for it, I have personally drank so called diet drinks before that raised my bg.

without knowing what your bg was before excercise its abit hard to judge.
you should really always test before excercise to make sure you bg isnt too low or high, if your bg is above 13 you should not excercise.

 

[Snodger]

I'd guess it's to do with when you injected...

Your body will be responding to the exercise by thinking you need more sugar, so it may well pour out some stored sugar from your liver. If you didn't have enough insulin sloshing around, the body can't use the sugar...so it thinks it hasn't got any... so it pours more out!
If you ate at midday and didn't have any more insulin, and you are on a standard quick-acting insulin, it will have stopped working by 18.30, probably. So any extra sugar your liver was adding to the mix would have just stayed in your blood.

Does that make sense? Let me know if not. Although it's counter intuitive, it could be that a small jab of insulin just before you go to the gym is what you need.

 

[pianoman]

There is a store of glucose in the liver (and skeletal muscles). If your exercise was intense enough to cause your BG to drop significantly, the liver may have released some of this glucose to compensate. But for those of us with impaired BG management, we tend to overshoot the normal ranges.

Not having eaten for several hours could well be part of the picture as well. I have heard that a snack before exercise can help prevent this. You would need to test to see what works for you though.

Exercise is a good way to use up Glucose (along with many other benefits) so don't be surprised to see a lower BG up to a day or 2 after intense exercise.... I have been warned that it is possible to go low.

 

[louiseb]

snodger the op doesnt use insulin, according to their profile and signature they take metformin only.

 

[RussG]

Very intensive exercise can often make your sugars go up temporarily afterwards. If your heart rate is going over 75% of maximum (quick calculation is 220 minus your age is your maximum) then you will most likely see a rise first, but then lower results over 1-2 days afterwards. I play raquetball and often go up after this. As long as it comes down after a couple of hours, I wouldn't worry.

http://runsweet.com/ has lots of useful advice about this.

 

[Fencer]

I tend to workout at around 60-90% of maximum heart rate. Yes, I'm on metformin only.

Today I have a less intensive session planned (45 min spin class), so may not get the same results as yesterday but I will definitely start testing shortly before and shortly afterwards to see what's going on here.

Just got a bit of a surprise to see it higher than normal when I expected it to be lower than normal.

 

[LittleGreyCat]

I peaked in the 11s the other day after a 3 mile run.
Could have been the banana I had before the run not being used up or a glucose dump.
Would have checked that out this morning but the battery has just gone phut in my meter.

 

[Snodger]

snodger the op doesnt use insulin, according to their profile and signature they take metformin only.

oops! sorry. please ignore me. *tries to remember that not everyone's type 1*

 

[louiseb]

snodger the op doesnt use insulin, according to their profile and signature they take metformin only.

oops! sorry. please ignore me. *tries to remember that not everyone's type 1*

hey dont be sorry, you were trying to help nothing to apologise for

 

[Sid Bonkers]

Pianoman and rglennon are spot on here I think, gentle exercise will more often than not lower bg levels but high intensity exercise will be more likely to increase levels especially after a missed lunch, muscles screaming out for glucose so your liver does its job and dumps its glycogen stores.

Try eating some carbs before your workout but dont overdo it, test test and test again

 

[Fencer]

Pianoman and rglennon are spot on here I think, gentle exercise will more often than not lower bg levels but high intensity exercise will be more likely to increase levels especially after a missed lunch, muscles screaming out for glucose so your liver does its job and dumps its glycogen stores.

This makes sense, I can understand this. But is it bad that bg levels are raising?

Mine were OK last night, but I won't really know until I have another night like Tuesday. We'll see how Friday is.

 

[LittleGreyCat]

Managed to do my test this morning.
[Remember kids, ask your parents before you try this at home.]

Fasting blood 08:03 - 7.6
Test just before run (nothing but coffee since last night) 10:05 - 7.1
Test just after the 3 mile run (quite hard and in the rain) 10:42 - 7.6

So if I don't have anything before my run my BG goes up slightly.
The results after a pre-run bannana were much higher.

Gonna try having a slice of malt loaf with my morning coffee then testing pre and post.

Cheers

LGC

 

[Sanober]

Pianoman and rglennon are spot on here I think, gentle exercise will more often than not lower bg levels but high intensity exercise will be more likely to increase levels especially after a missed lunch, muscles screaming out for glucose so your liver does its job and dumps its glycogen stores.

Try eating some carbs before your workout but dont overdo it, test test and test again

Thank goodness for this response! It makes sense to me as I tend to exercise pretty intensely as T2 I understand that insulin isn't being used properly - and I find my glucose is higher after. So I've started to eat something a bit more substantial before a workout (a banana/ a handful of nuts/oatcakse pre workout doesn't help and I can actually feel woozy/sick/off balance/heavy limbed and knackered) so I actually now eat a cheese or egg (wholemeal) sandwich - space it out over 3 hours - so half then 1.5 hrs later another half (leaving another 1.5hrs before the actual exercise).

Don't understand the science truly and if this really is a good way to do things but so far it's doing the job and I'm a lot more spritely! - also I eat handful of nuts straight after (water of course) and at the mo after exercise just eat a small portion of protein (and no carb at all due to past some awful high night readings after late exercise and eating) - so still experimenting on post workout food...

 

[RussG]

I played racquetball yesterday lunchtime, which is a very strenuous sport. my heart rate runs between 150 and high 170s (my max would be 183). I have found that something that seems to work - Boot's sell a sports bar that contains 25g fast acting carb and 25g slow release. As I'm usually in the 4-5 region by lunchtime, I eat one of these bars (sometimes with another 14g cereal bar if I'm at the lower end) and don't cover this with any insulin. This becomes my lunch. I was 4.3 when I ate the bar yesterday, 6.9 when I started playing, so I took a dextrose tablet for safety, and took another couple of detrose during the game. By the time I walked back to my office, I was 11.2. About two and a bit hours later I was 4.9 and have had really good results since - fasting BG was 1-2mmol lower than previous days.

Here's the relevant bit from http://www.runsweet.com
Fuel Regulation in Athletes without Diabetes
High intensity exercise includes activities above the lactic threshold with a greater reliance on anaerobic metabolism. Cathecholamines are thought to take over primary control of hepatic glucose production from insulin and glucagon during exercise of high intensity. This is recognised to cause hyperglycaemia even in individuals without diabetes, it is thought that dramatically increased cathecholamines trigger a relative overproduction of glucose. This can then be compensated for by an increase in endogenous insulin production.
Implications for Athletes with Type 1 Diabetes:
• Predisposition to hyperglycaemia
Unable to compensate by an increase in endogenous insulin production hyperglycaemia is common following short high intensity exercise in athletes with type 1 diabetes.

Having read that, my guess is that the same would still be true for T2s but with perhaps a different profile response.

 

[LittleGreyCat]

Managed to do my test this morning.
[Remember kids, ask your parents before you try this at home.]

Fasting blood 08:03 - 7.6
Test just before run (nothing but coffee since last night) 10:05 - 7.1
Test just after the 3 mile run (quite hard and in the rain) 10:42 - 7.6

So if I don't have anything before my run my BG goes up slightly.
The results after a pre-run bannana were much higher.

Gonna try having a slice of malt loaf with my morning coffee then testing pre and post.

Interesting.
Single sliced of malt loaf with plenty of butter about 20-30 mins before run.

Fasting blood 06:32 6.9
Test just before run 09:06 8.4
Test just after run (easier pace, sunny,4 miles in 33:42, gentle walk down) 10:08 6.1

So this looks quite promising.
Malt loaf before run, BG goes up but not too fast and then comes down by the end of the run.
One difference, however, is that I had a walk down after the run so the test was delayed about 10 minutes compared to yesteray when I bolted indoors dripping wet and panting.

I think I'll dig out my heart rate monitor and see what my heart rate is on a hard and a medium run.

Oh, and heart rate monitors were in Lidl this week at a reasonable price (unless it was Aldi - they both look much the same).

Cheers

LGC