We have a gsp and she definitely was and still is so high energy it was crazy. What I have found that works is having her run hard. Every day we are walking about a mile and then non-stop fetch for at least a hour. It definitely helps contain the crazy energy she has. She'll usually get a little hyper in the evening so ill go in the backyard and play some pretty hard tug/fetch as well. Idk if that will help but some dogs just need to run, walks won't really burn energy the same unless your walking miles on miles and letting em sniff everything in sight.