Isaiah 40

 Isaiah said of the Savior - 

"Hast thou not known? hast thou not heard, that the everlasting God, the Lord, the Creator of the ends of the earth, fainteth not, neither is weary? there is no searching of his understanding.

29 He giveth power to the faint; and to them that have no might he increaseth strength.

30 Even the youths shall faint and be weary, and the young men shall utterly fall..."  (Isaiah 40:28–30)

Obviously, Isaiah suggests that the Lord runs and is not weary and walks and does not faint in blessing and strengthening His children, thus, in my mind, those words mean of us that - 

"...they that wait upon the Lord shall renew their strength; they shall mount up with wings as eagles; they shall run, and not be weary; and they shall walk, and not faint."  (Isaiah 40:31)

I believe that to run and not be weary and walk and not faint is in reference to our diligence and effort in serving family and others.