It is common for members of a university club to be practicing effectively 2 or more hours per day. Over several years this brings pretty rapid progress. Gettin

It is common for members of a university club to be practicing effectively 2 or more hours per day. Over several years this brings pretty rapid progress. Getting to nidan is fairly common. But after they leave, the majority stop, or do maybe once a week at most. A friend of mine carried on to do a PhD, so was able to continue quite a lot - 20+ years later he is 6th dan!