Exercise and BG

It's all trial and error I'm afraid! You're doing exactly the right thing, test before and after and keep an eye on it later on in the day.

Only through time and recording your results will you get an idea of whether or not you need a Jaffa cake. Various factors such as your starting BG level, whether your BG level is rising or falling before you start and, crucially, how intense your exercise is.

Hi Hale,
As it was only 2.5km it may be that it was the excercise that increased your bg something to do with endorphines and adreneline. Next time try to do the excact same run and ditch the Jaffa cake, but make sure you bring something with you just incase. It really is trial and error. If i'm doing a slower run it's tiring but I'm not exactly dripping from sweat my bg can sometimes go slightly higher so i only need to turn my basal down to 90% instead of 60%. I try just to adjust my insulin instead of taking on carbs as I'm then just burning off what I've taken on instead of my bingo wings!!
For your levemir why do you reduce after you've had your run? I would have reduced the night before i was going to excercise although I may be wrong long time since I've been on injections.
Laura

It's not the distance of the run that will increase your BG levels it's the intensity. From my experience it works like this:

Minimal intensity over a short distance will have a slight impact on your BG levels but this will depend on factors such as what you've eaten before and whether your levels are rising or falling at the start. The further you go the more likely it is your levels will start to drop.

Medium intensity over any distance should result in a reduction of BG levels (again, allowing for factors above) and you may need to take some sugar during the exercise to counteract this.

High intensity over short distances (sprinting etc) will increase BG levels and you may need to take insulin before or during exercise to counteract. This is a result of our in built "fight or flight" instinct. Your body thinks "Holy **** we're running from something bad" and gives you more sugar to get you out of Dodge!

In the last week I have ran 8 miles at a comfortable pace during which I had 3 jelly babies and my BG levels were slightly lower afterwards and had a track session of 3 x 800mtrs where I took 2 units of insulin after the 2nd rep and maintained BG levels of around 8 during the session.

It is all trial and error. Reducing insulin after exercise is always recommended as BG levels can drop as a result. When I'm running regularly I can control my BG tightly but if I stop then there's generally a 48hr delay before they start to increase.

If you're jogging at about 60/70% of max heart rate runsweet suggests that your glucose level will fall in around 20-30mins. That totally accords with my experience of levels falling at about the 2 mile mark.
Personally, I wouldn't bother to eat anything at 6.3 if I was going to run that distance. I would just take one glucose tab at around that time. (Though I've a pump, and can alter the basal, I'm often not organised enough to alter the basal rate far enough in advance for short runs)BUT what I do is personal based on lots of testing.
I did do lots of testing at the beginning and now realise my symptom of hypos when running is a mental disinclination to continue.

I agree about reducing insulin after exercise, if not I tend to hypo at 5 hours.

As other said, it's trial and error. Take your meter and a source of sugar with you and test yourself half way round and at the end. You'll soon find out whether you need the Jaffa cake.

Hi Hale
I do a 20 minute run every day, and couldn't understand why on different days I got different results, then read this on runsweet, www.runsweet.com/AvoidingHypos.html (4. Integration of a 10 second Maximal Sprint).
Every time I finish with a big (ish) sprint my sugar rises afterwards, no sprint and they slowly fall for about an hour after. Just another possibility.