Isaiah 40:29-31 New King James Version (NKJV)
29 He gives power to the weak,
And to those who have no might He increases strength.
30 Even the youths shall faint and be weary,
And the young men shall utterly fall,
31 But those who wait on 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.