One thing we always train our dogs to do well, are hills. Living out here in the flat part of Canada, hills are a bit hard to find. But we look for any elevation during our runs and use them. Everything is training.
Here is a race that we were in, To the Loppet! . Many people in the race struggled with the hills. Stopping to herringbone up, and their dogs would look over their shoulders as if to ask "What's going on bud? KEEP UP!" But not our dogs...
Our dogs eat hills for breakfast.
It's simple enough, and this was a tip taught to me by a mushing mentor. During your training walks or regular runs, anytime you see a hill, take full advantage of it.
RUN AT IT! FAST! HARD!
Teach your dogs that hills are fun, and they should run at them. When you run at them, and get to the top, offer lots of praise, and then keep moving. You don't want to teach them to run up a hill, and stop. Once your dogs are pulling when they see a hill, offer a command for the behaviour as well. We use "HILL". Which means, to the Oxford Dogs," RUN! There's a party up there!"
You will be thanking me later when you are coming back after a long run, winded, and parked your truck on a hill. When the dogs see the hill, and get their second wind, your tired butt will be dragged right up after them.