Given an ultra takes a lot longer than 2 hours (the approximate limit of our carbohydrates to supply energy)
it is clear that fat is going to be a big contributor to our energy supplies.
The less effective we are at using fat for fuel the more carbohydrates we have to consume during a race to fuel our muscles. The more we have to put into our stomachs the more chance of stomach problems.
Given stomach upsets are a major causes of DNF’s and below par performances in ultras it makes sense to work on increasing your bodies ability to burn fat.
