Romans 8 reminds us we don't always know what to pray in some situations. Thank the Lord we can rely on His Spirit praying through us. We can trust when we pray in the Spirit we are following His guidance in prayer.
Isaiah prophesied of the refreshing that praying in the Spirit brings. Feeling "burned out"? Pray in the Spirit. The world system offers refreshing. Chemicals, pills, illicit affairs, all they offer bring with it much consequence and pain, and will never satisfy. Christ and His gifts bring true refreshing.
Again Isaiah prophesied of the rest and refreshing brought forth by praying in the Spirit. Feeling weary? Pray in the Spirit and enter into God's rest.