I am on Mac OSX, so I can't answer for windows users:
I added a custom keymap entry and set it to Ctrl+? + Ctrl+?, while the original default is Ctrl+- and Ctrl+Shift+- (which translates to Ctrl+ß and Ctrl+Shift+ß on my german keyboard).
One can simply modify it in the user keymap settings:
{ "key": "ctrl+left", "command": "workbench.action.navigateBack" },
{ "key": "ctrl+right", "command": "workbench.action.navigateForward" }
For the accepted answer I actually wonder :) Alt+? / Alt+? jumps wordwise for me (which is kinda standard in all editors). Did they really do this mapping for the windows version?