User blog comment:Aleksandr the Great/Skyrim on Kinect/@comment-68.193.77.6-20111206233026/@comment-142.227.221.130-20111215142727

to me the "mana bar" or magicka as the elderscrolls calls it is just mental fatigue and in combat you are using you mind more to identify threats and the like therefor while not enough to drain the mind it certainly is being used more then when you are just wandering around and therefor regenerates slower