Originally Posted by
terrymorse
Yes, here's a rough example graph of carbs and fat usage (grams/minute) by intensity:
Zone 2 is already gobbling up the carbs. It's worthwhile to know that you can still deplete your glucose in zone 2, so even zone 2 efforts of 90 minutes or more benefit from carb ingestion, mainly by reducing fatigue from declining blood glucose.
This is of course for carb adapated athletes.. fat adapted atheletes have been show to metabolize fat at a rate of as hight as 1.6g/min at 86% VO2max.. fat adapated atheles have shown fat metabolism as high at 1.8g/min in another study!
"Low carbohydrate high fat ketogenic diets on the exercise crossover point and glucose homeostasis"
Journal Frontiers in Physiology in 2023.
https://www.frontiersin.org/journals...3.1150265/full