listing page in breadcrumb of single item
(EDIT)
Drupal core will build breadcrumbs based on the menu structure. So if you manage to create a menu link for each of your activities, then Drupal core has you covered (see the answer by General Redneck).
If you don't want a new menu link per activity node, then you can use Path breadcrumbs or Crumbs, see below.
(/EDIT)

There are different modules that can help you with breadcrumbs, and I am sure more than one of them can help with this particular issue.

One of them is Crumbs. If you choose this, here are some steps for configuration (after enabling the module):


Go to admin/structure/crumbs/entity-parent, and specify the views page as the parent path for the node type of your choice.
On admin/structure/menu, edit the main menu (or another menu), create an item that links to the views page, and give it a title like "Activities". (*)
On admin/structure/crumbs, make sure that the menu.link_title.main-menu and menu.hierarchy.main-menu are enabled. Or just enable menu.*.
(enabling means to move those lines up into the "Enabled" section with drag+drop)
To see what going on behind the scenes, you can visit admin/structure/crumbs/debug.


(*) Creating the menu item is one option you have so that Crumbs can determine a title for the breadcrumb item that points to the activities view. There are other ways, but this is the most straightforward, and you probably want to create this menu link anyway.