The body needs a certain amount of movement to stay balanced. The mind needs a certain amount of stillness to achieve this.
While the goal of YOGA is Self-realization, a balanced yoga practice can help facilitate this.
Tantrik Yoga developed for those who were not renunciates or ascetics. Modern yoga is not completely renunciate, nor is it completely in the world. Instead, it falls between both, in a state of limbo.
I'm sure you are familiar with this if you practice some form of yoga. You may transcend your pain somewhat, but you do not transcend the world. And because the world causes pain, you end up using yoga as a means to cope. Nothing wrong with that, of course. I did it myself for years. But you have stayed where the pain was, and is, formed - in the world. You may sometimes experience release in meditation, but once it's over, you're back in the 'real world' again. It helps, of course, but it is not an awakened state of being. It's only partial.
Tantra is not about denying anything, even if it's painful. It's about using - whatever - to awaken to your true nature. And while Classical Tantra is not about sex, nothing is off the table. It's not about the activity, it's about using whatever activity to awaken.
Tantra is about cultivating energy. We incorporate this into a modern yoga practice in the form of practices which make us feel more alive. But herein lies the problem. When we approach a path which is actually about renunciation, which is what Classical Yoga is, we may end up feeling better due to a practice that renounces the world. We are attempting to renounce what we are attempting to make feel better. We feel better in a body-mind that we are attempting to transcend!
For years, I struggled with this dilemma, because I didn't understand the distinction. Once you figure it out, your practice will be sublime. You will relax into your being, into the moment, without struggling with contradictory paths often mixed up in a modern yoga practice.
You don't have to change what you are doing, only the way you approach it. Tantra is not about trying to remove something. It's not about becoming something else, although this will occur in its own good time with practice. Tantra will make your practice a much richer experience. If you decide you are not going to renounce the world, you allow the world to exist in you, as you, and awaken to your divinity. Learn how to connect with your divinity with Tantrik Yoga, including practices to cultivate your energy alongside Āyurvedic routines.
Yoga practice emphasizes breathing through the nose. If you are breathing through your mouth you are likely to be over-breathing. It is necessary to create an awareness of breathing patterns when approaching yoga. The benefit of placing the body in various postures is to expand the breath - by introducing particular energetic and muscular locks in the body.
Sometimes, you use the intercostal muscles (muscles between the ribs) more when breathing, expanding the ribs. At other times, you may be using your abdomen more, keeping the chest somewhat still.
You may find that you can remove all force and control of the breath and let the body's position dictate how you breathe. The breath is not forced, in that case, but is a natural result of the position of the body and the type of movement. As you slow down the breath, there is a natural pause between breaths. Without force or strain, you become a more efficient breather and a fitter, healthier and happier person.