I am cross posting from Trnsitions but some may not read there.
Here is my theory on fueling for long course racing.
There was a good blurb on theis written by PeePee* called Half Ironman Nutrition for Halfwits that I read just before my first long course race. It was very simple but if anything was probably a tad heavy handed on the carb allocation for my personal circumstances. Anyway, after some trial and error, some reading, a few threads here and some hocus pocus, I settled on the final formula for long course racing.
Water - 15ml/kilo/hour on hot days 10ml/kilo/hour not so hot days
Carb - 0.5-0.8g/kilo of body weight per hour
Salt - 1 gram/hr hot 1 gram/90 minutes not so hot
Concerntartion of carb in solution 0.5-0.8%
Now to give an actual physical example of what I mean, lets assume a 75kg person with a 5 hour duration event. The total intake would be-
Water - 75kg 10-15ml/hr = 75X10-15 = 750ml to 1125ml of water/hr
Carb - 75kg 0.5-0.8g/hr = 75x 0.5 to 0.8 = 37.5 to 60g carb per hour
Salt 3 to 5 grams total
Now, for the concentration of carb in fluid, that works out perfectly with 750ml and 37.5g carb = 5% and 1125 at 60 = 5.3% and at the other ends, the 1125/37.5 is well below 5% which is good and the 60g with 750ml is 8%. All good.
Things can get pretty technical from there with digestion efficiency V calorie intake and how that changes with intensity but that is not really anything that matters at this stage.
Here is my theory on fueling for long course racing.
There was a good blurb on theis written by PeePee* called Half Ironman Nutrition for Halfwits that I read just before my first long course race. It was very simple but if anything was probably a tad heavy handed on the carb allocation for my personal circumstances. Anyway, after some trial and error, some reading, a few threads here and some hocus pocus, I settled on the final formula for long course racing.
Water - 15ml/kilo/hour on hot days 10ml/kilo/hour not so hot days
Carb - 0.5-0.8g/kilo of body weight per hour
Salt - 1 gram/hr hot 1 gram/90 minutes not so hot
Concerntartion of carb in solution 0.5-0.8%
Now to give an actual physical example of what I mean, lets assume a 75kg person with a 5 hour duration event. The total intake would be-
Water - 75kg 10-15ml/hr = 75X10-15 = 750ml to 1125ml of water/hr
Carb - 75kg 0.5-0.8g/hr = 75x 0.5 to 0.8 = 37.5 to 60g carb per hour
Salt 3 to 5 grams total
Now, for the concentration of carb in fluid, that works out perfectly with 750ml and 37.5g carb = 5% and 1125 at 60 = 5.3% and at the other ends, the 1125/37.5 is well below 5% which is good and the 60g with 750ml is 8%. All good.
Things can get pretty technical from there with digestion efficiency V calorie intake and how that changes with intensity but that is not really anything that matters at this stage.