Following are a number of back-translations as well as a sample translation for translators of Isaiah 40:30:

• Kupsabiny: “A young man gets tired so the point of fainting
  and strength can run out for a young man.” (Source: Kupsabiny Back Translation)
• Newari: “Even people who are young children, having no strength, will become tired,
  and young men, having become tired, will fall down.” (Source: Newari Back Translation)
• Hiligaynon: “Even the young-ones/people get-tired, or weak, and they fall,” (Source: Hiligaynon Back Translation)