I'm in the process of researching what breed of dog to get. My wife and I have never owned a dog before so it's all new to us. One thing I often read is that a certain breed (generally the breeds I'm most interested in) will require a lot of exercise, but I'm never sure exactly what this means. We would certainly be taking the dog out for a walk twice a day, for 30 minutes or so each time, but other than that we would probably be limited to one longer walk a week (2-3 hours ish). I'd be happy to throw a ball around a bit during the walks too (I'd stop off at a park), and I'm happy to do some basic training, but I don't know how much else. I doubt I'd be up for the full-on obedience training / dog-assault-course stuff. So would this be considered enough exercise for a breed such as a German or Australian shepherd?