Fueling from fat (inscyd)

I watched your Inscyd video going over Chris and Trevors test and was interested in the part where is shows how much of your energy production is coming from fat or carbs for each power level. When power is being produced from fat, is that from fat on your body (because we all have fat stores)? Or is the from fats that you are eating? If its eating, what are some example ride foods that have good sources of fat for fuel.

Hi @Humunuku, welcome to the forum! Yes, your interpretation is correct. It is coming from our fat stores. In general during exercise at low to moderate intensities the triacylglycerol from stored fat is transported to the muscles for the fatty acids to be used for energy. The muscles can also use some stored intramuscular triacylglycerols to break down for energy, and we see that trained endurance athletes generally have better ability to combust fat as fitness increases. Here’s a nice visual overview from Dr. Asker Jeukendrup

In terms of eating, within endurance exercise, we have plenty of fat to support exercise needs, so carbohydrate is usually the limiting factor in performance, and that becomes the key macronutrient to consume. However, during very long/ultra-distance exercise, or in specific nutritional cases (e.g., taste fatigue), bringing in fuels with different nutrient profiles (more fat/protein, for example) can enhance overall energy intake while still providing carbohydrate.

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