Following are a number of back-translations as well as a sample translation for translators of Isaiah 40:31:

• Kupsabiny: “But those who trust in God,
  their strength will be added to.
  They fly away like eagles.
  They run without getting tired,
  and walk around without losing strength.” (Source: Kupsabiny Back Translation)
• Newari: “But the strength of those who put their hope in The LORD will be renewed.
  They will keep on flying upward and upward like eagles
  and even by going running they will not become tired.
  Also, by going for a walk they will not faint.” (Source: Newari Back Translation)
• Hiligaynon: “but the ones-who-trust in the LORD can- again -get strength. As-if they will-fly like an eagle; if they run they will- not -become-tired; if they walk they will- not -become-weak.” (Source: Hiligaynon Back Translation)