In tantric buddhism (vajrayana) empowerments (tib. lung) are given, not only for deities but also for other purposes, such as scriptures. When one has received a lung for a particular text, reading it becomes a practice where the natural state becomes revealed, because of the empowerment. There are no prerequisites for receiving a lung unless otherwise noted.
for Physical Exercise
This empowerment is to reveal the natural state during physical exercise. It is applicable to all forms of exercise, for example yoga, running, sports, swimming, martial arts, weight lifting and so on. After one receices this empowerment, it becomes active automatically when begins to exercise and lasts until the training sessions ends. No prayers or mantras are needed. Doing the exercise, putting the body under straing, is all that is needed.