For about the first week after whelping most of the European Doberman moms use all their energy cleaning the puppies, making milk, and making sure they're nursing. After that they have some excess energy that they love to burn off getting some exercise.
She's only recently liked the frisbee, it may be because we've been playing a lot more one on one which gives her more time with each toy. The pressure of the others European Dobermans chasing and competing for the same dogs is gone.
There's a big difference in the moms when they get some play each day compared to when they're not able to (if its storming or snowing). It really helps them be better moms to their pups, and stay happier.