Hatha Yoga Pradeepika Ch-2, Po-3

refer:

http://yog-knowledge.blogspot.com/2010/12/hatha-yoga-pradeepika-ch-2-po-2.html

Kumbhakas should be performed gradually 4 times during day and night, i.e., (morning, noon, evening and midnight), till the number of Kumbhakas for one time is 80 and for day and night together it is 320. In the beginning there is perspiration, in the middle stage there is quivering, and in the last or the 3rd stage one obtains steadiness; and then the breath should be made steady or motionless.

The perspiration exuding from exertion of practice should be rubbed into the body (and not wiped), as by so doing the body becomes strong. During the first stage of practice the food consisting of milk and ghee is wholesome. When the practice becomes established, no such restriction is necessary.