Hi Dean, I know how it feels having to pull out of a race because of diabetes. I missed last year's Stockholm Marathon mainly due to the fact that I was in hospital being diagnosed! You don't say whether you've done any long races before diagnosis, so I'm assuming not in the following.
I had to take a break from the running for a couple of months due to a problem with my heart (some very wacky ECGs!), which was particularly hard for me as I've been running for over 25 years, and had just trained up to 'marathon' levels before falling ill.
The main thing is to take things slowly, measure and record. Prior to diagnosis I just used to go out and run, usually before breakfast as the sun was coming up. Now, I don't really have that option as I have to eat breakfast and allow it to digest before I can leave the house. I usually wait about 1-2 hours after eating. I measure my BG and record it. If it's below 6'ish I'll have some orange juice. If above 6.5 I don't normally have anything extra. I can't say what I'd do if my level was high, because it hasn't happened, but the general advice is that if it is above 13 or so, then to wait until it comes down a little.
I then go out for my run! I've found that I can run about 5-6 miles without needing any extra top-up - I measure my levels when I get back and they are usually almost unchanged, or maybe a bit higher or lower. It's possible your levels will increase rather than drop due to the release of cortisol and adrenalin, depending on intensity - this is more likely on race day, when you are excited/apprehensive.
Beyond 5 miles I have a couple of jelly babies a mile. For a longer run, it's also important to drink, and I suppose you could take an energy/isotonic drink instead of the JBs, but I prefer to drink water. You'll probably find that, as your fitness improves, you'll be able to run further and further without it affecting your BG too much. Also, you'll become familiar with your routes and ability to cope over time, so it will become less of a chore!
I always take some jelly babies or glucose tablets out with me, plus diabetes ID, just to be on the safe side. I'm thinking of getting a 'Cram Alert' (
http://www.cramalert.co.uk/ ) to be extra prepared.
Regarding insulin - you will become much more insulin sensitive with the exercise, and this effect can last (in my case) up to 40 hours. So, after a run I will reduce my insulin by around 25% for the next three meals, and might also drop my basal by 10% that night. If I've done a particularly long run I might have to reduce my insulin by 35% - I found this out recently after stepping up my training!
Race days need different considerations. If your aim is London 2010, then I'd suggest you plan at least a couple of shorter races - 10k, 10m or half-marathons before then, so you can get used to the different things you have to do on an event. Usually, you have to be there long before the start - especially with a huge mass-participation event like London - so the food you have for breakfast will probably have been fully digested by then. Depending on how many hours prior to the event you have to be there, you might need to have a snack earlier, but then something more substantial when you arrive.
You also need to consider insulin - you need some 'circulating' insulin for the food to do its work. I'm just thinking aloud here, as I've only done the Great South Run since diagnosis, and that was a shorter race within the 'lifespan' of my breakfast and novorapid. But, I've run a lot of marathons and half marathons over the years and you can be kept waiting for ages. Before, it didn't affect me too much, but now I need to consider these things.
It's a little more complicated for me now, but the benefits are huge. I might have diabetes, but I'm in far better shape than most people I know of my age!
A good book to read is 'The Diabetic Athlete' by Sheri Colberg for information about how everything works when you're exercising
Good luck with the training - keep us informed of how it's going, and please ask any questions you might have - they might be very helpful to me and others!
🙂
