make demands of (one)
To put a great deal of pressure on one to perform at an extremely high level. This is a cutthroat business, and it makes demands of anyone who wants to excel in it. The coach makes demands of all the kids who play on his team, but they also have more championship titles than any other team in the state.
make demands of someone or something
and make demands on someone or somethingto expect someone or something to do something or act in a particular way. Please don't make demands of everyone in the shop. The boss is making a lot of demands on the new machinery.