Nailing Nutrition on the Bike to Run Fast
From a conversation with a triathlete:
The most important thing to consider is the grams of carbohydrates you are consuming per hour. 60-90g is recommended per hour of long course racing on the bike with the sweet spot for most people being 75g. You do want these carbohydrates from multiple sources which allows you to digest/oxidize the maximum number of carbohydrates through different pathways.
This is why you don’t want to use a single source carbohydrate. If you choose a single source you may limit your absorption/oxidation rate to 65% less than multiple carbohydrate sources. If you use three scoops of Perform mix per bottle you get approximately 50 grams of mixed carbohydrates. Add a gel per hour and you get 75g of carbohydrates per hour.
The ability to digest your ideal number of carbohydrates has to be practiced in training. You can train your gut to digest a lot of food while going fast (in long course racing we are never actually going that fast)!
If you have a power meter, you want to target consuming at least half of the kilojoules you burn in calories (they are roughly equal in a bizarre mathematical coincidence). Remember, the power meter does not account for the calories/thermal energy of the body so add 10 to 20% more calories to your total calories burned.
At Texas, my total work on the bike was 2821 kilojoules in 5:32. I consumed 81.8g of carbs per hour and 327 calories per hour. Total calories consumed on the bike was 1800 calories. I practice this on any long ride (over 2 hours of aerobic work) or any day where my total training includes over three hours of aerobic work. I achieved my goal this season to get my consumption up and over 80g of carbohydrates per hour.
Nailing nutrition on your bike is the key to running fast!