I urge you to plan for [early morning prayer]. Think ahead what the time will be. Win the victory the night before, not in the morning. Decide the evening before when the alarm will call you from sleep to prayer.

The discipline to rise early is not as difficult as the discipline of going to bed. This did not used to be so. Before electricity and radio and television and the Internet, going to bed soon after dark was not so difficult. There wasn't much to do. Today the strongest allurements to stay up and be entertained are against us. Therefore, the battle against weariness, which makes us drowsy as soon as we open our Bible in the morning, has to be fought in the evening, not just in the morning. When you have decided when the alarm will call you to prayer, then decide when you must go to bed so that you are not exhausted when the alarm goes off. If you need caffeine to keep you awake in the morning, I will leave that with your conscience. Maybe that's why God created it. Staying awake to pray is certainly a better use of caffeine than staying awake for almost anything else.

John Piper, When I Don't Desire God: How to Fight for Joy, pp. 161-62