To rise on eagle's wings, you know what that means? Often when eagle swoop down they open their wings and depends on the wind to glide them. It is not by their strength but by the strength of the wind. This is why the verse says run but not weary and walk without being tired. When I ride on God's shoulder and become dependent on Him, He gives me the wind to continue. I can run for Him not because I have power or might, but because I have His mighty wind guiding me through.