When you hit pre-maintenance, you add 10 carbs per week until you begin to gain slightly, then drop back. You are searching to find your number of carbs you can consume without gaining, since once you are on maintenance you don't want to lose more or gain any. So, you might not be able to lose above 40, but you might not gain until you get over 70, for example. So, you would want to keep your lifetime carbs per day under 70 most of the time.