Isaiah 40:29-31 ESV
He gives power to the faint,
and to him who has no might he increases strength.
Even youths shall faint and be weary,
and young men shall fall exhausted;
but they who wait for the LORD shall renew their strength;
they shall mount up with wings like eagles;
they shall run and not be weary;
they shall walk and not faint.
ESV: English Standard Version 2016