Too much exercise?
My 10 month old GSD/sheltie doesn't really care for leashed walks and barely breathes harder after a brisk 1.5 miles but LOVES hardcore fetch and would go for hours if I let her. Problem is, I don't know her genetic background (she's a rescue) and short of x-raying her hips I don't know what kind of condition they're in.
I'm wondering, is one hour of pretty serious fetch everyday too much for a 10 month old puppy (she runs like her life depends on it)? And is there another way of exercising her without hurting her? I know I'm not supposed to jog her until at least a year old (not to mention she's disinterested in human-speed trotting), and walking does absolutely nothing for her exercise-wise - instead of napping after a 45 minute walk she wants to do zoomies in the backyard.
She also gets about 20-30 minutes of obedience training most days and I ask for quick little obedience things between throws (sit, down, back up, focus, etc.).
Also, is it possible that her exercise demands have increased since I got her because I have been exercising her more than the shelter/rescue?