Yin Yoga & The Rebound Effect
This may be the most important part of a Yin Yoga practice.
It's called the rebound, and it's a short period of rest after a single Yin posture. In its simplest form, you just lie down on your back to feel the after-effects of a pose.
The experiences people have in the rebound can range from relaxation to euphoria. So what is it, and why is it so powerful? The best way to understand it is to experience it in your own body. Here's a guided yin session which has long holds of 4-5 minutes and long rebounds of 1 minute or more.
To understand what's happening in the rebound, we can start with its more familiar variation: savasana.
How the rebound is like Savasana
The rebound resembles a short savasana, which is a period of rest and stillness customarily done at the end of a yoga practice. Savasana (pronounced sha-VA-sa-na) typically lasts for 1-10 minutes and is intended to integrate all the energetic and physical sensations one might feel after a sequence of yoga postures.
Savasana is a Sanskrit word that literally means "corpse posture," and in yoga it usually indicates lying down and remaining still – like an expressionless, non-living body.
But in modern yoga, savasana has taken on a dual meaning: in addition to the physical posture it describes, yogis also associate it with a particular state of deep relaxation – a state that only happens at the end of a yoga sequence.
There's something special about this time. For many people, after awakening the subtle energies of the body during the posture sequence, they can access an exquisitely deep state of calm in savasana. There can often be vivid inner sensations like floating in space or dissolving into one's surroundings. A yogi might also feel strong sensations of movement, even though the body is completely still.
Savasana can be a special and intimate time to engage with one's own inner energy. This might be why many yogis say that Savasana is their favorite part of a yoga practice
How the rebound feels
In Yin Yoga, instead of the familiar savasana that's done all at once after a full sequence of postures, the yogi takes a shorter savasana after each posture. Many yin yoga teachers call the rebound. A typical timing is to hold each yin posture for 2-5 minutes, followed by a 1-minute rebound, but there can also be variations on the timing.
After releasing a pose, the sensations a yin yogi feels can be stronger than what she felt while holding the pose. These sensations might arise in different parts of the body and are described as tingling, warmth, fullness, expanding, contracting, or a number of other inner experiences.
The rebound is often done while lying on the back in savasana, but it can also be done in other passive positions such as child's pose, resting on the belly, or resting with legs up the wall.
The rebound is one of the most accessible forms of meditation available. The sensations of the rebound arise naturally and can completely absorb the practitioner's attention and awareness, resulting in a fulfilling time to recharge.
Many Yin Yoga teachers do not include rebounds as part of their sequences and instead move from one pose right into the next. In my 20+ years of teaching Yoga I've come to see them as indispensable, and when I guide my online Yin Yoga Teacher Training I recommend that trainees integrate them into every sequence.
The science of the rebound effect
What's really happening inside during the rebound? Yogi scientists Paul Grilley and Bernie Clark discuss this as a change in the "phase" of the body's fascial fluid – the water that runs through and around the fascia. The change is from a "gel" phase (more viscous) to a "sol" phase (more liquid). Yin practice and other forms of myofascial release are believed to encourage this change.
The result is that the tissues becomes looser and release tension, which for many people feels like a state of relaxation and calm. In my studies with Paul Grilley he has said that Chi is the link between the physical and the astral bodies. It has a dual nature. That's why the rebound after a pose can be felt physically and is also emotionally and mentally calming.
But for some people, this gel-sol change can create sensations beyond relaxation, such as floating. This makes sense in terms of the gel-sol change since fascia is suspended in a more fluid environment than usual. The feeling can even be hallucinogenic as the body transforms into a less grounded and more dynamic state.
The gel-sol phase change is a temporary state that's healthy and beneficial to the body. Similar to rinsing a sponge out, when we do yoga we squeeze and compress the body's tissues to discharge stagnant fluid and soak up fresh fluid.
According to the Modern Meridian Theory proposed by Dr. Hiroshi Motoyama, the meridians of acupuncture flow through the fascial fluid, and the rinsing process renews the body's Chi.
A more Western view on what's happening is called the Relaxation Response – a phenomenon studied by Dr. Herbert Benson, who describes it as an activation of the parasympathetic nervous system. The Relaxation Response is the opposite of anxiety and stress. In deep states of relaxation, your body and brain heal and repair themselves from stressful periods, releasing chemicals and brain signals that make your muscles and organs slow down while increasing blood flow to the brain.
A mystery that continues to unfold
In all the years I've been guiding yin yoga journeys, I've learned that what yogis see, feel and experience during the rebound can be wildly different from one person to the next. This makes me think there may be a more complex network of energetic forces not yet understood by science that's responsible for this variety of euphoric feelings.
I don't claim to understand it, but I like to imagine that these sensations are some kind of manifestation of our individual life force – our essence energy – expressing itself.