I have always found this balance really hard, - how long you can leave it when you've eaten before exercise, do you sit about knowing you're going high etc.
I'm not sure I have the answers to be honest but the things I'd try are:
- can you move your meal to be a bit closer to kick-off, so the spike isn't as high for as long?
- can you do some exercise in the meantime between meal and kick-off, eg running/cycling to the football ground, so you are keeping the spike reasonably under control?
the only other thing I've tried is injecting the normal amount and then drinking lucozade or something immediately before exercising, but I don't think that's the answer at all coz it gives you no overall stamina.
If you find the answer let me know!