Sometimes circumstances demand a few hours of creative and concentrated mental activity while the mind is lethargic. Many people under these circumstances resort to caffeine or television in the hope that they can find the groove. Some college students wrongly use prescription drugs for ADHD, like adderall, to focus. The scriptures, according to Shri T. Krishnamacharya, say that Pranayama is a good way to stimulate and recharge the nervous system especially when there is a lot of "tamas" (intertia). In fact, yoga sutra 2.52, states the following:
This is the reason that during the middle years of one's life from 35-60, when many people see a droop in mental alertness through doing repetitive work, Pranayama is prescribed as a remendy to remove the Aavarana (veil) of the intellect. Three rounds of 10 nadi shodhana pranayamas is supposed to cleanse the nadis of the aavarana.
Another way to recharge the nervous system is to do backbends. The second series of ashtanga vinyasa yoga is called Nadi Shodhana for the reason that the first sequence of asanas in this series are backbends, culminating in kapotasana followed by supta vajrasana. Forty five minutes of asana practice with emphasis on backbends, after warm up, can recharge the nervous system. Upon reading these statements one may ask the following two questions:
i) Very few people can do any backbends at all, due to the spine becoming stiff and curved forward from our lifestyle of drooping before a computer or looking at a phone, let alone do the intimidating asanas like kapotasana (dubbed "nightmareasana") and supta vajrasana.
This is a legitimate concern and the answer is that one need not do advanced asanas to gain the benefit but relatively simpler asanas like Urdhva Dhanurasana will help. That said, scriptures like the Bhagavad Gita and classic yoga texts like the Hatha Yoga Pradipika use the term "Shanaih Shanaih" which means "slowly, slowly" to say that one should endeavor slowly slowly without being scared of the seemingly mountainous task (please see the video below to see and hear the Shloka from the Bhagavad Gita). Though in the context of the Bhagavad Gita the mountainous task is to get the mind to settle down, the same analogy can be used for the body opening up and becoming s little more pliable.
ii) Where do I have 45 minutes let alone 30 minutes when I am working under a tight deadline ?
Nature's solutions are never quick fixes unlike popping a pill or drinking a cup of coffee. It may seem like a cliche. However yoga practitioners (practicing with the right mindset) experience a refined feeling of joy and satisfaction from tapping into and harnessing the body's prana. For them, using excess of harsher stimulants like coffee, become less attractive in spite of the instantaneous wakefulness, which again comes with a lot of mental agitation.
I hope this article serves as a motivation for backbends. Please see below for the videos of a few backbends.