I don't want to sound like a jackass, but you'll find out with time. In the magical land of jiu jitsu, or to put it better, my area in this MAGICAL REALM, the one where gringos don't come to train, some schools only train 3 times a week, and I know I train in a school that is the exception. 4 times a week is a lot of training, and you can make a lot of it. If it's too much for you, you'll find out, if it's too little, same thing.