"Bhikkhus, there are these five benefits of walking meditation. What are the five?

  1. One is able to endure long journeys,

  2. one is able to endure striving,

  3. one is seldom sick,

  4. what has been eaten, drunk, chewed, and tasted is properly digested, and

  5. the collectedness attained by walking meditation is long-lasting.

These, bhikkhus, are the five benefits of walking meditation."

A practice of walking meditation is part of the fourth training guideline: Training in wakefulness of the gradual training guidelines.

When, Brahmin, a bhikkhu is moderate in eating, the Tathāgata further trains him: ‘Come, bhikkhu, remain devoted to wakefulness. During the day, purify your mind from obstructive states through walking meditation and sitting meditation. During the first watch of the night, purify your mind in the same way; in the middle watch of the night, lie down on the right side in the lion’s posture, with one foot overlapping the other, mindful and fully aware, after noting in your mind the idea of rising; in the last watch of the night, rise up and continue purifying your mind from obstructive states through walking meditation and sitting meditation.’"

Gradual Training, Gradual Practice, and Gradual Progress (MN 107)

A training guideline should be practiced in gradually to see gradual progress.