Hope I'm not stealing this thread. If so, pls ignore my post. What is recommended fuel for long century ride? Coconut oil, cold pressed, is touted to be MCT. Would it work if mixed into water bottle instead of carb drink? I find it difficult to eat reasonably well on long ride.
For everybody else who didn't have a PhD in nutrition, biology, etc, MCT stands for "Medium Chain Triglyceride". I'm not, I just happened to have done some research lately on fat metabolism and came upon "MCT" dozens of times and I still end up googling the acronym up.
MCT is a type of fat that goes directly to the bloodstream when eaten. It doesn't get stored up as body fat but used as energy.
HOWEVER, you will only benefit from MCT if your body is well adapted to fat metabolism, ketosis, and under ketosis. Note that you don't ease your body into ketosis overnight. The adaptation process takes months. It will be months before your body can comfortable slip into ketosis without any problems. Thus, if you've never done ketosis either by ketogenic diets or by intermittent fasting, you're at least a couple months away before you can take advantage of MCT.
Even then, the benefit of MCT is marginal. Your body will usually have way more than energy stored in body fat (before it gets dangerously low) to do three centuries without eating. Obviously, man does not live on fats alone, you'll probably run out of other essential nutrients long before experiencing serious calorie and fat deficit if you try a triple back to back centuries without eating.
You can have way too much of fatty acids in the blood because your body can't metabolize them fast enough even as a highly trained athlete on ketosis.
The only people who could possibly be benefitted by eating MCT or ketones during rides are extremely lean, keto-adapted athletes maintaining their minimum body fat % in the race season. The MCT / ketones can help keep their body fat % at healthy levels and not dipping dangerously low.
The one advantage of fat-based fuel is the weight. You get over twice more calories in a gram of fat vs gram of pure carb. You only have to carry less than half of fat-based fuel in terms of weight to get the same amount of calories.
Again, this advantage is diminished if you're doing a supported ride since you won't have to carry all the weight of your needed fuel.
But on long, self-sufficient rides with only very few to no stops, then ketosis / fat metabolism is king but ONLY if your body is fully adapted to it. The fact is exemplified in nature through migratory birds. Their long, non-stop flight is almost powered entirely by fat metabolism, even under high exercise intensities. Many don't eat nor drink during these very long non-stop flights which can be hundreds of miles at a time or even farther.
