We've all heard, time and time again, that yoga and meditation is great for us. I mean, it doesn't take a genius to see the physical benefits. Increased flexibility, elongated, toned muscles and improved breathing techniques spring to mind. Not just that, but have you ever met a yogi who's hot headed, grumpy, stressed and not full of peace and love?
In light of my upcoming journey to Goa to attend a 5 day detox retreat, I wanted to understand the deeper meaning behind the 'inner peace' and relaxation yoga and meditation seem to improve. And why is it that studies have shown those who consistently practice yoga and meditate throughout their lives are generally less stress and less affected by disease?
Firstly, we have to look at what causes people to become stressed, those who, ironically, are best suited to practising yoga and meditation. Apart from living a stressful lifestyle, the primary causative effect of stress on the body comes down to the over release of stress hormones such as adrenaline and cortisol, thanks to stimulation by the sympathetic nervous system (SNS). This causes a variety of changes in the body including increased heart rate, blood pressure and blood glucose levels. Don't get me wrong, as I've mentioned before, this release of stress hormones from the SNS is sometimes essential (e.g. running away from a pack of lions), but in this fast paced world it can become a chronic issue when over-indulged.
Many yoga positions and meditation techniques are designed to combat this chronic SNS release by increasing the effects of the parasympathetic nervous system (PNS). The PNS allows for recovery after a stressful event by slowing the heart rate, breathing and lowering blood pressure. Sometimes known as the relaxation response, this release helps balance the blood flow back through the entire body and helps everything recover and rest; essentially the 'rest and digest' response as opposed to the 'flight or flight' response of the SNS.
Secondly, we have to consider more of the endocrine system and the glands that create and release hormones within the body. Lets work from the top, down (quite literally).
The Pineal gland is located in the middle of the brain, our 'super control centre'. The pineal gland is said to control day-to-day rhythms and is affected by light, synthesising and releasing melatonin - which anticipates the daily onset of darkness and aids sleep - and serotonin - which mediates not only gut movement and appetite, but mood (it's all connected...more on that another day!). Certain yoga poses stimulate the pineal gland, which not only contributes to improved sleep, but can help with issues related to the gut and control appetite. It can also improve mood and reduce anxiety by balancing the release of serotonin.
Next is the Pituitary gland. Small but mighty, this gland is located at the base of the brain, and is often referred to as the 'Master Gland'. The posterior portion of the Pituitary relays information from the hypothalamus, a part of the brain that coordinates the nervous system (PNS and SNS) with the glandular system, and controls the body's reaction to emotional states by sending information to endocrine glands. The anterior pituitary synthesises and releases hormones. For example, human growth hormone (HGH) stimulates growth and muscle repair. Thyroid stimulating hormone (TSH) triggers hormone release from the thyroid gland (to come...). Adrenocorticotropic hormone (ACTH) principle effects are increased cortisol production and release, controlling blood pressure. Prolactin is released to literally increase lactation and breast milk production, and Gonadotropins are hormones that regulate sexual function in males and females. The hormones released by the pituitary gland mediate metabolism (thyroid gland), water balance via the kidneys, temperature regulation and pain relief. Certain yoga poses and meditation techniques can help to balance the pituitary gland, which can also aid in weight loss and regulate bowel movements.
The Thyroid and Parathyroid glands control the metabolic rate in the body, how quickly chemical processes occur, as well as body temperature and energy produced. A slight over secretion in the hormones released by the thyroid can cause irritability and nervousness, while an under secretion can cause lethargy and fatigue. Gentle massage of the thyroid through particular yoga poses can help moderate the release of the most common thyroid hormones, Thyroxin (T4) and Tyrosine (T3), in turn improving metabolism and organ function.
The Adrenal glands play a massive role in stress. Located just above the kidneys, in a fight or flight response they release adrenaline that causes increased blood pressure and heart rate, divert blood flow away from the digestive system and to the large muscles so they are ready to move and run, stimulates sweat glands and dilates pupils (literally so you can see better). If the adrenal gland is insufficient it can reduce one's ability to respond effectively to a crisis, however if it is over stimulated it can cause negative stress induced effects on the body. Adrenal glands also release cortisol and aldosterone, steroid hormones released in response to stress, that increase blood sugar, repress the immune system, aid in metabolism and increases water retention, blood pressure and blood volume. If consistently over stimulated by the SNS, release of such hormones can have chronic detrimental effects to such bodily functions, which is why stimulation of the PNS due to yoga, to counteract these effects, is imperative.
The Pancreas is located below the stomach and releases digestive enzymes into the small intestine. It also secretes insulin, a hormone that moderates blood glucose levels. If the pancreas is not effective and does not release enough insulin, blood glucose levels cannot be contained and will result in diabetes mellitus.
Finally, the Gonads are basically the sexual reproductive organs of both males and females - testes and ovaries. Not only do these glands produce sperm and egg follicles, but also release male and female sex hormones - androgen and oestrogen respectively. Androgens increase muscle mass of the body and appear to induce aggressive behaviour. Oestrogen increases fatty padding and pay induce passive behaviour (see my previous post on other effects of oestrogen). The correct balance of these hormones is essential in human development and behaviour modification.
So why did you just sit there and read about hormones for the past 10 minutes? Well, the human organism is controlled by hormones. Every function, every system, every organ, every tissue, even every emotional perception is guided by hormones. If a hormone release is imbalanced, it can disrupt the delicate balance of the body, not only affecting physical functions but also psychological responses. Imbalanced hormones can cause anxiety, depression, insomnia and mood swings. The yoga positions incorporating twisting, bending and turning can help massage, strengthen and regulate endocrine glands, helping to moderate and control their hormone secretions. Meditation and steady, deep breathing can help stimulate the PNS, suppressing the SNS and over release of stress hormones. Thanks to yoga and meditation, many common ailments can be cured and harmony and balance can be restored to the body. Before you know it, you'll be well on your way to being a chilled out, healthy, happy yogi!
V x
