Re analogies I prefer bank account. You have an amount of money in the account. The rate at which you spend it determines how long it lasts. You can make additional depoisits but they take time to clear. The trick is to balance spending of carb reserves with depoisits such that you are empty/slightly overdrawn at the end.
I thought the matches thing was a different effect on your muscles, that there was a limit to how many intervals you could do above your threshold regardless of your carb intake. I.e. necking a couple of gells doesn’t necessarily buy you another match but will get you through another few miles at/below threshold power.
If you continued the bank account review, you’d start with £1000(calories) credit, and burn them / replace them through the day. But at certain times you could take out a short term loan (oxygen debt rather than calorie debt) rather than draw on the current account, but at a point you piss off the bank manager and he cut’s off your credit.
