The yoga of awareness. Kriya yoga accelerates spiritual growth with energetic practice of breath control, chanting and mudras (hand gestures). Kriya technique identifies three practices as being essential to spiritual progress: discipline, self-study and surrender to a higher power. Kriyas are techniques to free the mind of impurities that impede serenity.
Practicing kriya yoga creates tapas (heat) in the body by focusing acute attention on mind, body and consciousness. Examples of kriya techniques include meditating while holding a mudra, rhythmic breath practice and free movement that links breath with body.
The repetition of om and meditating on its meaning is the way.
Yoga Sutra 1.28