The Collaborative International Dictionary of English v.0.48:

Invigoration \In*vig`or*a"tion\, n.
   The act of invigorating, or the state of being invigorated.
   [1913 Webster]

WordNet (r) 3.0 (2006):

invigoration
    n 1: quality of being active or spirited or alive and vigorous
         [syn: animation, spiritedness, invigoration, brio,
         vivification]
    2: the activity of giving vitality and vigour to something [syn:
       vivification, invigoration, animation]