Here is an excerpt in which the Buddha encourages monks to be aware of the body and use the body to help develop awareness in addition to their anapanasati or mindfulness with breathing practice.
The Body as a Body
“Again, bhikkhus, when walking, a bhikkhu is aware and knows: “the body is walking;” when standing, he is aware and knows: “the body is standing;” when sitting, he is aware and knows: “the body is sitting;” when lying down, he is aware and knows: “the body is lying down;” or he is aware and knows accordingly however his body is disposed.
Again, bhikkhus, a bhikkhu is one who acts in full awareness when going forward and returning; who acts in full awareness when looking ahead and looking away; who acts in full awareness when flexing and extending his limbs; who acts in full awareness when wearing his robes and carrying his outer robe and bowl; who acts in full awareness when eating, drinking, consuming food, and tasting; who acts in full awareness when defecating and urinating; who acts in full awareness when walking, standing, sitting, falling asleep, waking up, talking, and keeping silent.
In this way he abides knowing and understanding the body as a body internally, externally, and both internally and externally… And he abides independent, not clinging to anything in the world. That is how a bhikkhu abides knowing and understanding the body as a body.”
From the Satipatthana Sutta
