When we attend a sesshin, a period of intense Zen practice, we will begin the day with a fast-paced morning kinhin. Although usually only about ten minutes in length, the pace is too fast for the obese or physically unfit. We will then have a drink of water and go the meditation hall, or zendo, for the first sitting of the day.
So we prepare for the fast kinhin in our daily practice at home. In Advanced Zen, after completing our Beginning Zen kinhin and our warm-up exercises, we take a brisk walk. We have a glass of water afterwards and go to our private meditation hall as soon as we finish our morning walk. An invigorating thirty minute walk is recommended.
Zen practice requires vigor. Only a healthy, vibrant body can sit perfectly still. The cultivation of vigor or energy is also the fourth factor of the Seven Factors of Enlightenment.
The energy referred to in the Seven Factors, however, is a different quality of energy. It arises from sustained meditation, and primarily through practice of the Four Foundations of Mindfulness.
We therefore walk or jog every morning after warming up using the Eight Form Moving Meditation to help us prepare for the retreats that we will be attending, and to develop and maintain the fitness level we need to enable us to sit motionless during our daily meditation practice.
Physical fitness is an important part of Zen practice. The length and pace of the morning walk is up to us. Thirty minutes is probably an effective minimum. An hour feels even better. The athletic nature of a walk or jog is secondary; the primary purpose is to develop the habit of walking or jogging in the morning after performing the beginning and intermediate zen warm-up practices.
As advanced practitioners who by now have read and studied Mindfulness, Bliss and Beyond, we know that the first two of the four jhanas are recognized by feelings of intense joy at the first jhana and by feelings of a more stable and serene happiness at the second jhana.
No amount of advanced physical training will take us into the first and second jhanas because the pleasant feelings we generate fall far short of the intense experience of those two jhana states.
Still, it is instructive to note that as we insulate ourselves from falling into the tenth dharma realm, we are forming a foundation for the experience of the first two jhanas.