"I have a friend who does Morning Prayer on the treadmill. Years and years of it have committed the recurring portions of it to his memory. He starts up the belt and starts walking: 'Lord, open my lips. And my mouth shall proclaim your praise.' He goes through the whole office, and then spends the rest of the time on the treadmill in intercessory prayer: for himself, for his friends and family, for his church, for everything, saving the appointed psalms and readings until he gets back home and can sit down and read them. The pounding of his feet on the moving rubber belt becomes music, the percussive continuo accompanying his prayer.

"He's done this for a long time, so long that he has become conditioned to it. Now, when he jumps on his treadmill, it makes him want to pray.

"Interesting: we can condition our spirits in the same way we condition our bodies. At the same time, in fact. We can train ourselves to pray, to fall into prayer as we fall into a familiar step. We can imprint our prayer lives right on our muscle memory."