In the Ashtanga tradition, yoga should not be practised when the full moon is out and energy levels are correspondingly low. Yoga teacher and practitioner Inna Costantini looks at the age-old beliefs surrounding moon days
Most yoga practitioners now seem to be familiar with the argument that it's good to avoid doing yoga on full or new moon days.
This ritual habit of avoiding so-called "moon days" derives from Pattabi Jois' Ashtanga Yoga system, which states that the body may be exposed to increased risks of injury at either extremes of the lunar cycle.
On a personal level, I've always been somewhat sceptical on the effects of the moon cycle on people's health and wellbeing - perhaps as a resistance to my mother's continuing belief that our moods and feelings are deeply affected by the lunar cycle.
When growing up, I was told that a dark moon would equate to low energy levels and grumpiness, whilst a full moon led to high energy levels - and, frequently, arguments with my father. It was as if the moon would justify any changes in my father's attitude, and hers to some extent.
So when it came to yoga, especially when I started practising Asthanga, I was initially wary about any ‘moon day' theory.
However, after some research - and much practice - I soon noticed some variations in my body on particular days. The theory is that because the body is made of 70% water, it is affected in the same way by the moon as oceans and tides.
In fact, the lunar cycle is determined by the moon's relative position to the sun. Full moons occur when they are in opposition and new moons when they are in conjunction, and both sun and moon exercise a gravitational pull on the earth.
Tim Miller, a long term Asthangi and the first American certified to teach by Pattabhi Jois, very accurately points out in his reserach on moon days:
'The full moon energy corresponds to the end of inhalation when the force of prana is greatest. This is an expansive, upward moving force that makes us feel energetic and emotional, but not well grounded.
'The Upanishads state that the main prana lives in the head. During the full moon we tend to be more headstrong. The new moon energy corresponds to the end of exhalation when the force of apana is greatest.
'Apana (or downwards energy/prana) is a contracting, downward moving force that makes us feel calm and grounded, but dense and disinclined towards physical exertion.'
So ultimately, according to this theory, the best time to practice would be in the middle of the lunar cycle, when prana is more balanced.
According to the Asthanga Yoga system, one should not practice on those days, as the body is more vulnerable to injury - either through tiredness/lack of energy or too much of it and a risk of over-exertion.
Traditionally it was also a way to give oneself a rest; Asthanga being a strong, physically demanding practice.
In other forms of yoga, moon days are not always respected but usually acknowledged as times of fluctuating energy, unsettled moods and hence not ideal for strong physical practices.
I have often been surprised by the lack of knowledge people have on moon days. Even though I'm hardly experienced myself, I believe that being committed to a sound practice should lead to a deeper understanding and listening of one's body.
Recently, I woke up on a morning following a dark moon feeling lethargic, slow, scattered and unmotivated. At the same time I respect that my body needs this day of rest, slowness and ease. Moon days can be seen as honouring nature, and thereby one's relationship with the world.
And the same goes for growing vegetables or planting trees - biodynamic farmers respect the moon cycles, while most serious gardeners will acknowledge that the moon does have some effect on the ways plants grow.
So without being utterly superstitious or sounding like a new age hippy, I would recommend everyone reads up on moon days and starts to observe the effects these times have on your practice - you might even surprise yourself.
For further information see: www.ashtangayogacenter.com
Inna Costantini is as Ashtanga yoga teacher and practitioner.