Your brain uses about 150g of glucose per day. Your body also constantly metabolizes glucose, even while you sleep.
Considering lifting for an hour will burn at most 400 calories (probably <80g carbs), you might consider decreasing your carbohydrate intake by the amount of carbohydrate intake based on your workouts... or not, since your blood only holds about 20g of carbs at baseline and your glycogen stores are probably low anyway.