A.W
Could you check the GU gels you are using are 20mg per gel and not 40mg of caffeine per gel (thought that the flavour you are currently using are the double caffeine ones? - 40mg per gel). Just want to check as even the 40mg would be fine to use but would like to know in case there is issue with stomach etc.
Plan at moment is a gel in Paris at miles: 6,11, 16 & 21 this is a total of 100grams of carb or 33g per hour which as you are well trained may well be enough. As we discussed I would like you to carry 5 in case you lose one or feel need another one.
Will post a carb loading day later this week/ early next week so you can practice before half in Feb - this should be your full dress rehearsal for Paris. Race breakfast, what you eat the day before etc
Have a good few days and sorry to any one if missed any nutrition questions, bring to my attention again!