Balasana - Child's Pose

Sun and Moon

Just like the sun and moon, everything has an internal source of energy. In our bodies, the sun and moon occupy opposing halves similar to the concept of yin and yang. The moon represents the left energy channel (ida nadi) and the sun represents the right energy channel (pingala nadi). Our goal is to achieve and maintain BALANCE between both.

"As above, so below. As without, so within."

Sun and Moon

Sun and Moon

Just like the sun and moon, everything has an internal source of energy. In our bodies, the sun and moon occupy opposing halves similar to the concept of yin and yang. The moon represents the left energy channel (ida nadi) and the sun represents the right energy channel (pingala nadi). Our goal is to achieve and maintain BALANCE between both.

"As above, so below. As without, so within."

The Yoga Sutra of Patanjali

The Yoga Sutra of Patanjali
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Pranayama

4. PRANAYAMA: the fourth limb of The Yoga Sutra of Patanjali
Prana is the energy or life force that exists everywhere and flows through every living thing that breathes.  Pranayama is how we control the breath.  Inhalation, retention of breath, and exhalation are the basic movements of pranayama.  "The yogi's life is not measured by the number of days, but by the number of breaths... Therefore, he follows the proper rhythmic patterns of slow, deep breathing."  -Lyengar.
Pranamaya clears the mind for meditation.
biomedicalephemera:

Top-down view of lungs and surrounding anatomy.

Niyama

2. NIYAMA: the second limb of The Yoga Sutra of Patanjali
Niyama is inner discipline and responsibility, loving ourselves.  There are 5 niyamas.

• Purity(shauca).  Purity is achieved through the 5 yamas, which rid your mind of negativities.  Keep yourself, clothing, and environment clean.  Eat fresh, healthy meals.  Your body is a temple. 
• Contentment (santosha).  Be content with what you have and be happy with who you are.  Seek happiness in the present moment.
• Austerity (tapas).  Be disciplined in body, speech, and mind.  This helps us learn control thus enabling us to direct the mind and body for higher spiritual goals.
• Study of the sacred text (svadhyaya).  Study sacred texts of your religion, or what you find engaging, that's relevant to your spiritual growth.  As lyengar says, a person starts to "realize that all creation is meant for bhakti (adoration) rather than for bhoga (enjoyment), that all creation is divine, that there is divinity within himself and that the energy which moves him is the same that moves the entire universe."
• Living with an awareness of the Divine (ishvara-pranidhana).  Be devoted to God, the divine universe, and what you consider holy.

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Yama

1. YAMA: the first limb of The Yoga Sutra of Patanjali
Yama is social behavior, how you treat other people and your environment. Apply the golden rule.  There are 5 yamas.

• Nonviolence (ahimsa).  Do not harm any creature in thought or deed. Including insects.  Compassion for all creatures.  Refrain from gossip and practice patience, kindness, and tolerance.
• Truth & Honesty (satya).  Do not lie or cheat.  Refrain from deception. Live with integrity, sincerity, and clarity. Seek your dharma, your purpose.
• Non-stealing (asteya).  Do not steal material objects or intangibles such as attention or credit.
• Non-lust (brahmacharya).  Avoid meaningless sexual encounters.  See divinity in all.  Moderation in our actions.
• Non-possessiveness; non-greediness (aparigraha).  Identify, deconstruct, and cleanse yourself from greed and hoarding.  Make your life simple.