Dr. Wesley L. Duewel- Praise renews Your strength. Waiting on God and hoping in Him renew you spiritually and often physically also (Is. 40:29-31.) Praising God is often even more effective than prayer in refreshing, reviving, and empowering you.
Every Christian at times experiences a sense of spiritual dryness. Certainly, after a spiritual battle, there is mental and emotional exhaustion. (Google image, I will sing to the Lord)