Read about the great revivals of the past -- or individuals who experienced great empowerment by God (think of Hudson Taylor for one of many) -- and you have to appreciate what it cost to bring it about. Hours of prayer into the night, or begun very early, some on knees or face. Hours. Five, six, seven hours. The whole eldership of a church in one case meeting for such protracted prayer two days a week while an elderly lady of the congregation and her sister prayed in concert with them at their home. (Notice something here. Since both men and women met together in the Upper Room, separating the sexes is no doubt not necessary in all circumstances, but I think it's interesting that in this case the men prayed separately and the praying women didn't join them. But then it was specifically the elders of the church. It is not said but I suppose the women covered their heads in those days. This was in Wales or Scotland, I forget, I just remember a few of the particulars.)
They prayed like that for months before God answered but He did answer in great power, the kind of power that moves people to seek God without a word's being spoken to them. They showed up at the church drawn by a power they knew not what.
Such exertions of individuals for the power of God are often not described as the reason God empowered them, or not described in terms of dying to self at least. We may hear about what they were doing before the blessing came, praying and studying the Bible for instance for long hours at a time, or what they were asking for in prayer, or how many got together. And sometimes their actions aren't even given as explanation, just as descriptive fact, but it seems to me the key in all the cases is the dying to self that they went through, the hours spent, the comforts abandoned.
There is sometimes a specific giving up of comforts mentioned in some of the stories, sleeping less, eating less or less luxuriously for instance, much fasting. Or there is the story how under the prompting of the Holy Spirit a man is moved to give up his last dollar to help someone else in need although having himself no prospects for his next meal. Thrown absolutely on the Lord's care at such a time the man learns that He provides -- in a way that is never really learned until all human means are exhausted. It always happens that way.
Revival can come to individuals as well as whole congregations and communities, though that's not usually the word for it. It's the same phenomenon though.
John 12:24 Verily, verily, I say unto you, Except a corn of wheat fall into the ground and die, it abideth alone: but if it die, it bringeth forth much fruit. 25 He that loveth his life shall lose it; and he that hateth his life in this world shall keep it unto life eternal.
Matthew 16:24 Then said Jesus unto his disciples, If any man will come after me, let him deny himself, and take up his cross, and follow me. 25 For whosoever will save his life shall lose it: and whosoever will lose his life for my sake shall find it. 26 For what is a man profited, if he shall gain the whole world, and lose his own soul? or what shall a man give in exchange for his soul?