get going

A favourite family saying of Joseph P. Kennedy (1888-1969), US politician, businessman, and father of President John F. Kennedy.

Joe [Kennedy] made his children stay on their toes. ‥He would bear down on them and tell them, ‘When the going gets tough, the tough get going.’
[1962 J. H. Cutler ‘Honey Fitz’ xx.]

Baron Marcel Bich, the millionaire French pen magnate probably spoke for them all last month when he said, ‘When the going gets tough, the tough get going!’ (‘Quand le chemin devient dur, les durs se cheminent!’)
[1970 New Yorker 3 Oct. 33]

‘When the going gets tough, the tough get going?’ she asked slyly. ‘Make fun if you want to, but that's what character is all about.’
[1979 J. Crumley Last Good Kiss xvi.]

‘I realize we're lost. ‥But always remember—“When the going gets tough, the tough get going”!’ ‘I know. But which way do we go?’
[2001 Washington Post 26 July C13 (Hagar the Horrible comic strip)]

Related to: opportunity, taken; politics; stress

Bibliography of major proverb collections and works cited from modern editions is available here.

1.  See get a move on.
2.  get something going. Start something, get something into full swing. For example, Once we get production going we'll have no more problems. This usage also appears in when the going gets tough, the tough get going, meaning that difficulties spur on capable individuals; the first tough here means "difficult," whereas the second means "strong-minded, resolute." For example, That problem won't stop Tom; when the going gets tough, the tough get going. Also see swing into action.
3.  Make someone talkative or active, as in Once he got her going on her grandchildren, there was no stopping her. [Colloquial; late 1800s]

The verb has 2 meanings:

Meaning #1: begin or set in motion
  Synonyms: start, go

Meaning #2: start to be active
  Synonyms: get cracking, bestir oneself, get moving, get weaving, get started, get rolling