Sleep is something dear to everyone. Very rarely is someone willing to sacrifice sleep. Ask about the preciousness of sleep to new mothers! We always wonder: What causes sleep? How much sleep do we need? What happens when we stay awake for a long time? These are questions we keep asking. One of our regular program participants always wanted to “conquer” sleep to work more and be more productive.People who visit the ashram ask us “How long do you sleep? Do Yogis sleep?”. These are questions that don’t have one single answer.
Have you heard of the circadian rhythm? It is the internal clock that enables several changes in the body based on the environment. It is very much related to the changes in the light. Our mood, behavior etc depend on the circadian cycle. Our sleep is also related to our rhythm. The circadian rhythm tells when to wake up, sleep and eat. Several processes in the body including body temperature and metabolic processes are coordinated by the circadian rhythm to ensure that we stay awake during the day and sleep during the night. This rhythm also varies from person to person. That is why some are “morning people” and some are “night people”.
Melatonin, called the hormone of darkness, helps in kickstarting sleep. After dusk, there is a lot of melatonin released into the bloodstream and gradually it reduces as we near morning. Once sunlight falls on the eyes(or eyelids), the secretion of melatonin stops and this helps us to wake up.
As we stay awake the levels of Adenosine keeps building up. This increases the desire to sleep. The more we stay awake, the more the “sleep pressure” or adenosine build up. When this reaches a threshold, we fall asleep. Stimulants like coffee block this adenosine build up and hence we seem to stay awake longer when we drink coffee but once our liver clears up the caffeine, the adenosine build up takes over and we fall “dead asleep”.
But why is this a problem?
A yogic way of life is one where the harmony of the body and mind is a key factor. Overdoing sleep or wakefulness is not helpful and especially if this involves stimulants like tea or coffee. Any strong chemicals put into the system creates huge damage. Strong medication, strong food or even strong emotions can destabilize the system. Harmony, happiness and balance are extremely important to the Yogi.
The Bhagavad Gita calls for a moderation in food, activity, entertainment and sleep to reap the benefits of Yoga.
नात्यश्नतस्तु योगोऽस्ति न चैकान्तमनश्नत: |
न चाति स्वप्नशीलस्य जाग्रतो नैव चार्जुन || 6.16||
युक्ताहारविहारस्य युक्तचेष्टस्य कर्मसु |
युक्तस्वप्नावबोधस्य योगो भवति दु:खहा || 6.17||
O Arjuna, those who eat too much or too little, sleep too much or too little, cannot attain success in Yoga.But those who are temperate in eating and recreation, balanced in work, and regulated in sleep, can mitigate all sorrows practicing Yoga.
Sleep in the Indian tradition
Be it the Upanishads or Yogic texts, sleep has been given due importance. It is recognised as one of the states of consciousness and a vritti according to the Yogasutra of Maharishi Patanjali.
अभावप्रत्ययालम्बना वृत्तिर्निद्रा ॥ १.१०॥
abhāvapratyayālambanā vṛttirnidrā || 1.10||
Sleep is a vritti that is supported by or based on absence of content (cognising emptiness). It is still a process different from the state of Samadhi because there is lack of awareness or there is awareness of only darkness. Sleep is a tamasic state while the deep state of meditation is a sattvic state. By knowing the state of sleep and dreams or by deeply reflecting on dreams and sleep, one gets a better understanding of meditative state says Patanjali Muni (स्वप्ननिद्राज्ञानालम्बनं वा ॥ १.३८॥ , svapnanidrājñānālambanaṃ vā || 1.38||)
In the Tattva Bodha, Adi Sankara Bhagavatpada describes deep sleep as a state where we aren’t aware of anything but we wake up and remember the experience of sleep. The identification with the karana sharira is still there which enables this remembrance. Dream is defined as the state where the experiences gathered during the waking state are projected and the mental processes are still on.
स्वप्नावस्था केति चेत् ? जाग्रदवस्थायां यद्दृष्टं यद् श्रुतम्
तज्जनितवासनया निद्रासमये यः प्रपञ्चः प्रतीयते सा
अतः सुषुप्त्यवस्था का ? अहं किमपि न जानामि सुखेन मया निद्राऽनुभूयत इति
svapnāvasthā keti cet ?jāgradavasthāyāṃ yaddṛṣṭaṃ yad śrutam
tajjanitavāsanayā nidrāsamaye yaḥ prapañcaḥ pratīyate sā
ataḥ suṣuptyavasthā kā?ahaṃ kimapi na jānāmi sukhena mayā nidrā’nubhūyata iti
Modern science talks of waking, sleep and dream states. When we lie down in our bed, we initially doze off. This is stage 1. Then the heartbeat slows down and overall metabolic activity is reduced. This is stage 2 when the body temperature is also lowered. We then enter into deep sleep where the body is in complete state of rest and we are unaware of outer surroundings. It is hard to wake up in this state. This stage of deep sleep is also extremely restorative in nature which rejuvenates the body and mind. This stage is characterized by slow and deep delta waves. All these are non Rapid Eye Movement Stages (NREM)
The brain then picks up activity similar to the waking state and this is the dream state. However, the voluntary activities are curtailed (else we would sleep walk).
Deep sleep leads to rejuvenation. The practice of Yoga Nidra which is a deeply relaxing practice is highly recommended to rejuvenate the body and mind. There are several Yogic practices to ensure that one gets enough rest during the day and night. Learning them from an expert can be very beneficial.
You can access Anaadi’s Yoga Nidra instructions here.