Too much exercise?

[Chennypenn]

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?

[Msmart]

I wouldn't think that its to much for your pup. I find the mental stimulation wears my pups out a lot more but they also get plenty of exercise. As long as you are giving them plenty of water and allowing them to go at there pace and not pushing them (like a long jog would) they should just fine. Hope this helps.