The two events take place in Sapporo, which still has emergency Covid measures in place.
Organisers said "to reduce the risk of infection" they would restrict "the movement of members of the public".
The Games, delayed a year because of the pandemic, start on 23 July.
Event organisers said they had met police and local government officials to discuss arrangements for the race walk events, which take place on 6 August, and the women's and men's marathons, which take place over the following two days.
