"When the going gets tough, the tough get going"
is a popular proverb in English. According to Wikipedia:
The phrase is a play on words involving idiomatic (Proverb) and distinct meanings of "go" and "tough." In context, "the going" means "the situation," "gets tough" means "becomes difficult," "the tough" means "people who are strong or enduring," and "get going" means "become fully engaged." Taken together, the meaning of the phrase is "When the situation becomes difficult, the strong will work harder to meet the challenge."
How can we translate that into German? Since this is a play on words, we shouldn't hope to retain all aspects of the proverb. Nevertheless, we can try to get close.
Wenn der Gang zäh geht, gehen die Zähen los.
What do you think? Any other (elegant) suggestions?