Reported speech- how to mix and match past with future

What is the correct and normally accepted way to report direct speech when the action is yet to take place.
Reported speech is always in the past tence-- for example
She said " blah blah ..." said / verb must be in the past, but what should you dowith the speech part of the verb if the action is yet to happen ?

She said to me "Tom is going to go running tomorrow"
She said to me "Tom will go running tomorrow"
" " " " "Tom is running tomorrow"
....or are all of these correct and independant of the first part ? sometimes the more you think the more confused you get !