Along the studies of Yoga, I came across Kriya Yoga, an ancient yoga system, and I found it is attributable to various Sources & Concepts. I decided to sort it out-

-According to the Gita, in Chapter 4 Verse 29, Kriya Yoga is attained as Liberation through Disjoining of Expiration & Inspiration (Prana into Apana and Apana into Prana leading to Neutralization of both); it talks of Karma Yoga too, as a Science of creating Internal Riches (Dam, Sham, Titiksha, Upreti, Shraddha, Samadhan)

-According to Patanjali, the three niyamas of Tapas, Swadhyaya & Ishwara pranidhana constitute Kriya Yoga, i.e. Self-Discipline via the Body, Self-Study via the Mind & Self-Surrender to the Lord; to move from Self-Ignorance to Self-Realization.

Hatha Yoga provides the Mudra practices to perform in Kriya Yoga; leading to Kundalini Yoga

Kriya Yoga, as devised by the Guru & clan of Paramhansa Yogananda, of Autobiography of a Yogi fame, refers to the Pranayama technique by Shyama Charan Lahiri, or the Babaji’s distinctive 18 Postures of Kriya Hatha Yoga

Kriya Yoga popularly comes across as a series of Detoxifying Poses to be performed in a special order, as designed & propagated by yogic outfits; ideally it is a compilation of the powerful practices of Hatha yoga, Tantra yoga, Mantra yoga & Raja yoga, performed in a definite sequence to systematically induce Pratyahara, Dharana, and Dhyana.

I now know Kriya Yoga to be a Psycho-physiological Method involving Clarification & Purificatory Processes of the Body and the Mind, by the use of Asanas, Pranayama, Mudras & Bandhas, as they Transmute the Cells, the Blood, the Brain & the Spine, leading to Liberation of Energy & Spiritual Awakening.

Following are some excerpts I gathered that threw light on the understanding –

“If you do external activity we call it karma. If you do internal activity we call it kriya. In a way, both are certain kind of karmas or both are certain kinds of kriyas. But traditionally, or in the general sense of the term it is understood like this: karmas are those which bind you, kriyas are those which release you.”

“But if you want the kriya to be a live process, if we want the kriya to be imprinted into your system in a certain way, then it needs discipline and dedication. It needs trust to open up your energies to the other person so that you become absolutely vulnerable. He may do anything with you, and initially, you will start wondering what the hell he is doing with you because the initial stages of kriyas can be such that you don’t know whether you are getting enlightened or you are going mad. You must have enough trust to sustain through those periods. Otherwise, kriya will be difficult.”

“Kriya yoga is important only if you want to do things beyond realization. If your interest is only to somehow escape this prison and get away, you just want enlightenment or mukti, then you don’t really have to walk the kriya yoga path because kriyas are so elaborate and involve so much discipline and focus. If you just want to be liberated, then kriyas can be used in a small way, it need not be too intense.”

 “If there is someone alive who can do things with you, then it can happen in this life.”

“People who have come up on kriya have a completely different kind of presence about them because of the mastery over their energies. They can dismantle life and put it back together. But if you are just pursuing other ways, like jnana, for example, you are razor-sharp, you can do many things with your mind but still, there is nothing much you can do with your energy. If you are on bhakti , there is nothing you can do and you don’t care, you only want to dissolve. If you are on the path of karma yoga, you do many things in the world, but you can do nothing with yourself. But kriya yogis can do whatever they wish with themselves in terms of energy and they can do a lot with the world also.”

“People have always known that the mind can be influenced. In the practice of kriya yoga, you try to influence the mind through the body. When you try to change the mind through the mind, it is raja yoga. When the mind is influenced through self-enquiry, it is gyana yoga. When you transform the mind through emotion, it is bhakti yoga. When you try to change the mind through selfless service and detachment, it is karma yoga. When you change the nature of the mind through herbs, it is part of tantra yoga. When you try to influence the mind by adjusting and balancing the chemicals of the body, that is hatha yoga.”

“The practices of kriya yoga are the easiest, the best and the most powerful. Kriya yoga is most suitable for the people of these times because it does not lay down any restrictions regarding food, habits, marital life, etc. By following the path of kundalini yoga and practicing kriya yoga, you can awaken your spiritual personality without interfering with your mind. Let your passions, jealousies, pride, and prejudice continue. Live with your depressions and elations, pleasure and pain. They do not stand as obstacles on the path of spiritual awakening.”

“In the practice of kriya yoga, you are not at all concerned with the distractions that are tossing within your mind. If your mind lacks the fundamental qualification of concentration and is swayed by passions, depressed by worries, psychotic or neurotic, even if you are on the worst of mental planes, it makes no difference in kriya yoga. Whether you are tamasic, rajasic or sattvic, it makes no difference.”

“In raja yoga, you have to be constantly aware of the functions of the mind. You have to make your mind consistent and one-pointed, otherwise, you will fail. But in kriya yoga the constancy of the mind is not important; you are concerned with the practices only. The practices are done on the physical plane and the mind has minimum involvement. It is not necessary to be consistent and one-pointed, but you have to practise the kriyas in the manner specified.”

Kriya yoga is essentially a set of around 20 exercises, involving Vipareeta karani mudra, Chakra anushadhana, Nada sanchalana, Pawan sanchalana, Shabda sanchalana, with Maha mudra & Maha bheda mudra being the main practices of Kriya yoga.