Normally if I have a dextro energy tablet, in about 20 minutes I start to speed up lots.
Unless it's the middle of the night....
I necked two dextro energies half way through a double lap at dusk til dawn last weekend. It would have been about 2.30am. For most of the lap I was half asleep, thinking 'any minute now, any minute now I'll wake up and speed up'... they kicked in in the last MILE after I'd spent a good 50 mins really struggling against the sleep deprivation and general exhaustion. B*stard!!!!
8% glucose solution is what you need, Kirstie - gets there faster than solid. A pinch of salt in the bottle will get it there sooner still. It's to do with stomach emptying speed. You can use unsweetened cordial to mask the taste (pineapple works well), and maltodextrin (i.e. PSP22) is less likely than ordinary glucose to cause gastrointestinal distress (8% is a moderately high concentration).
It's supposed too. Hill and Mountain climbers swear by it, It doesn't freeze in the cold, doesn't melt in the heat and is basically pure sugar in a bar.
Years ago when I was into photography they always used to say to pack a bar of it if you were going off into the wilds to take pictures.