Forget fast-paced ashtanga or sweaty Bikram - slow, simple yin yoga is the class to choose if you want to calm the mind and stretch the body. Just make sure you wear some warm clothes
The benefits attributed to yoga - increased flexibility and strength, more energy and better posture - should be enough to get anyone on the mat, especially now there is a plethora of classes to choose from if you want to work on your core, break a sweat or even learn handstands. But what is on offer for those who just want to relax, or runners and amateur athletes who want the benefits of stretching without exhausting themselves for future training sessions?
Yin yoga can complement an already active life or help those who feel distracted by "mind chatter". Constantly emailing, texting and posting social media updates has led, for some, to mental overload and a feeling that we are not good enough or achieving enough. Yin yoga can provide an antidote to this.
Ten years ago, there was but one regular yin yoga class in London. Now there are about 50, and classes are springing up around the country as people feel the need to slow down and just "be".
The term "yin yoga" comes from the Taoist tradition. Yang relates to movement, often repetitive movement, creating heat in the body. Yin is about finding stillness and cooling the body. And, the theory goes, we need both to come into balance to stay in optimum condition.
Running and cycling are yang activities. Even some vigorous forms of yoga, such as ashtanga vinyasa and Bikram yoga (the hot one!) are - arguably - overwhelmingly yang. But if you focus only on the yang, your body can suffer from fatigue and burnout.
Yin yoga is practised sitting or lying on the floor. There are no planks, no warriors, no core work. No dynamic sun salutations. No standing poses. The pace is slow, so you need to wear comfortable, warm clothes and maybe keep your socks on. The classes should be suitable for beginners and more experienced practitioners alike.
You can expect forward bends with legs together or apart, lunges and gentle backbends - poses that are commonly practised in dynamic yoga classes. But here's the key difference: in yin yoga, they are held for a longer period of time to increase flexibility in that part of the body. Instead of holding for five breaths, as in an ashtanga vinyasa class, in a yin class they could be held for between two and 20 minutes, although five is more usual.
Yin yoga also dispenses with the Sanskrit names of the poses in favour of descriptive English. So in one class you will encounter evocatively named poses such as butterfly, swan, dragon and twisted roots.
The reason behind these longer holds involves a short lesson in anatomy. Our bodies are made up of yang and yin tissues. Muscles are yang, so in order to be strengthened they must be subject to yang activity (repetitive movement, creating heat). Shorter holds, dynamic stretching (eg sun salutations) and running, cycling etc target yang tissue - muscles.
Longer, static holds enable us to access yin tissue - fascia and connective tissue. We need the combination of yang and yin to keep the joints healthy. Teeth are an example of a very yin part of the body. If you wanted to change and shape the position of your teeth, you wouldn't knock or hammer away at them quickly, but rather apply extremely gentle pressure over a long period of time - months or years (ie bracing).
So what is fascia? Fascia is the buzzword in the anatomy world. For so long, we were educated in muscles - how to stretch them and how to build them. But our muscles are encased in fascia, a continuous web of tissue that weaves in and around not only our muscles but also our organs, nerves and lymph. It is rather like a silk body stocking, only it is inside our bodies. The whiteish, sometimes glistening fibres you see when you pull a piece of meat apart - that is fascia. And to keep it healthy and springy, we need to keep it hydrated and we need to apply pressure to it with these longer holds.
Yin yoga was developed by teachers for students of meditation who found it too painful or difficult to sit on the floor for long periods of time. It is no surprise, then, to learn that yin yoga - while being a very effective way to open tight hips and hamstrings - also goes hand in hand with mindfulness practices. Teachers of yin provide guidance during the class showing people how to observe the breath and use this as a way to focus on the present moment, allowing thoughts and feelings to arise but practising the art of sitting with them and watching them without getting "involved" before letting them fade away. The "mind chatter" is lessened and the "volume" turned down on persistent and negative thought patterns. The hope is that we develop mindfulness skills that can be transferred from the mat to everyday life. When we are stuck in worry or frustration, we can bring the same kind of attention to the sensations of the body and the workings of our mind and stay with them for a time.
On a mental and emotional level, the practice allows the body to drop down into the parasympathetic nervous system, and therefore becomes deeply healing and nourishing. Practitioners report that it is grounding, calming and revitalising, with profound energetic and emotional effects.
Yin yoga is a simple, quiet practice, but - make no mistake - it is not always an easy or comfortable one. One of the leading teachers of yin yoga, Bernie Clark, says: "Yin yoga is not meant to be comfortable; it will take you well outside your comfort zone. Much of the benefit of the practice will come from staying in this zone of discomfort, despite the mind's urgent pleas to leave."
But if you can stick with it, people who regularly attend yin yoga classes say it stimulates perception and awareness of the quality and joy of the breath, and therefore of life itself.
Yin yoga poses are floor-based. Photograph: Debra Mcclinton/Getty Images