Quebec's three-stage reopening plan is made up of a gradual shift in COVID-19 zone colours over the next three months.
It's not yet clear if Montreal will be among the regions turning orange by end of May.
Currently, gyms in orange zones have to keep an attendance register of clients, and face masks are mandatory in training rooms.
Indoor fitness activities can be carried out alone, in pairs or with members of the same household.
"This is a plan that is being implemented cautiously and gradually," Legault said.
"We have seen that over the last few weeks, generation by generation, Quebecers have shown up, have done their civic duty."