I don't think taking him for a quite walk after dinner will
hurt him. It's the vigorous games of fetch & hard running till
he pants games to have to avoid. Reflux & bloating are serious
health issues to avoid in big dogs. Most behavior sites will tell
you this is a dog dominence issue, but I think it can also be just
nervous energy & lack of any other way of relating to you, the
new person in the house. One other cause I did find is that it
can be a behavior caused by some illness or medication used
to treat the illness. I feel sorry for the dog if he acts this way
all the time.

p.s. I would never Alpha roll any dog, even my own. It's never
a good idea.