Hi Curriespencer,
I’m the Dietitian for Uphill athlete and will try to give you an answer to your questions. What you will discover is, that when it comes to nutrition there is never a straight forward answer. I would tend to agree with Scott above, advise needs to be tailored to the individual and you will need to practice using the guidance to find what works best for you, your goals for body composition, training adaptations and the main event/s you are training for.
Firstly here are a couple of science papers to get your teeth stuck into;
‘Fuel for the work required’ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5889771/
Carbohydrate requirements during sport
‘Carbohydrate intake for training and competition’ https://www.ncbi.nlm.nih.gov/pubmed/21660838
‘Toward a Common Understanding of Diet–Exercise Strategies to Manipulate Fuel Availability for Training and Competition Preparation in Endurance Sport’ https://journals.humankinetics.com/doi/abs/10.1123/ijsnem.2018-0289
‘Carbohydrate availability and exercise training adaptation: Too much of a good thing?’
https://www.ncbi.nlm.nih.gov/pubmed/24942068
What you have proposed is 3 different nutrition goals you are trying to achieve which will all impact nutrition intake/requirements; *body weight loss, fat adaptation and understanding your own carbohydrate needs to support training adaptations (*weight loss is not the same as fat adaptation).
Looking at your data you have presented, you are utilising approx. 98g of carbohydrate per hour. When it comes to standard guidelines re carbohydrate intake per hour, the recommendations are 30g-90g per hour. You can absorb 1g of glucose per min but with glucose/fructose combined you can absorb approx. 1.26g/min because glucose and fructose have two separate absorption pathways. However it is not a direct translation of what you have used during training to what is required to ingest per hour. As your endurance training continues, what you would hope to see in your figures is a reduction in carbohydrate utilisation during an endurance session and an increase in fat usage (this is fat adaptation).
To enhance fat adaptation endurance training per se will aid this, but also carrying out zone 1 & zone 2 sessions fasted will optimise fat adaptation. You will find a great article on how to introduce fasted sessions on the uphill athlete website, I would advize reading these before you set out to do any fasted sessions. For high intensity sessions, zones 3 & 4 it is best to consume carbohydrate during these sessions because of the intensity you are training, depending on the intensity and duration on these sessions will influence carbohydrate requirements per hour. Zones 1 & 2 sessions not carried out fasted I would aim to introduce carbohydrate intake around 60-90mins into the session and start with 30g carbohydrate per hour, experiment with the recommended values and see how you get on.
To answer your question on Highly Branched Dextrin, it is a form of maltodextrin. The research on this shows that it has been shown to prolong blood glucose levels, it may reduce perceived rate of exertion during endurance training, it is faster absorbed by the gut and can also be better tolerated by those who may experience GI upset during training/event.
I hope this has answered your questions?
