Targetted ketogenic Diets mean eating carbs before and after exercise. The amount and type depend on the intensity and duration of the exercise. If you are not planning to do much work above 65-70% intensity, you don't need any extra carbs. If you are, you need enough to fuel the difference between what the fats in your diet can supply, and your workout needs.

However, everyone is different, so you'll need to experiment to see what works best for you.

For instance, if you were planning a fast three hour cycle, then you might take in 50g or so of a low-gi carb like oatmeal. If you are doing boxing or karate or something similar, then you might go for 20-30g of a higher-gi carb beforehand. If you are planning a hard lifting session, you probably won't need as much, since you'll have rests between sets, so 20g should be plenty.

Afterwards, you can take another protein and carb meal. After lifting, I strongly recommend a shake of whey and dextrose (about 30g whey, 10-15g dextrose). This should be absorbed by the body so rapidly, it won't affect ketosis.