Some dog lovers  use weights, such as a backpack, to train their dogs
in relation to aggressive behavior, or to use the backpack to drain some
energy prior to doing any training or exercise involving another dog.
Exercise level seriously impacts a dog’s overall behavior (as it does
with humans.

Living in NYC with a dog that can’t go to the dog run, it is sometimes
difficult to get them tired and happy.
I want to see this dog get enough physical exercise every day that he
is panting, but the FOUR HOURS of walking every day that he gets
doesn’t even impact him (unless it is hot outside).

Still, after everything that I have read, I would caution others about
using weights unless you really know what you are doing.
You don’t want to cause any joint or muscle problems.
I would rather see people work harder to get the dog more exercise,
but that’s just my position.
If people do choose this method, I agree with what you have said about
gradually getting the dog adjusted.
I would compare it to running. You wouldn’t just take a dog (or human)
who has never run for a 5 mile run. You would gradually work him into
it.
And if a human starts running and they don’t know what they are doing,
they can cause some serious damage to their body.
After considering the potential problems, I decided not to do it, and
just find another way.
Now that the weather is nice, I am thinking of roller blading instead.

General