I contacted my friend google and my vet-friend for this one:
Hip dysplasia occurs frequently with GSDs, but it should be a concern for the vast majority of dog owners. I would argue that exercise is crucial to preventing this particular health problem (and many others). Not only will exercise keep your dogs weight down, but it can help strengthen the muscles around the joint.
Of course, too much running and jumping could potentially cause a problem for some dogs. If your concerned about your dog, consult your vet! Dogs who are getting on in years a more susceptible to hip injuries. Also, german shepherds bred from “show lines” (i.e., those with the slopping back that was deemed a desirable trait for a time by the AKC) are more likely to develope a problem than their “working line” counterparts.
TDLR; German shepherds definitely NEED exercise and, unless your dog is more predisposed than others, exercise will help keep him/her healthy!
If you’re an active person who will make sure your dog receives enough exercise and mental stimulation, yes! But, these dogs can be a handful and a lot of them end up at GSD rescues and shelters because their owners underestimated them.