That is a part of what long distance running and cycling training accomplishes: shifting your consumption to a higher mix of fats vs glycogen at the same intens

That is a part of what long distance running and cycling training accomplishes: shifting your consumption to a higher mix of fats vs glycogen at the same intensity level. (To avoid the pedantic "buts" here, yes, your body is still consuming a lot of glycogen when you're running a marathon, but it's also using fats at a much higher % than it would in a 400m).