02/26/2012 10:51 am ET Updated Feb 26, 2012

World Yoga Day 2012: Good For The Community And Good For You

This Sunday marks the annual World Yoga Day event -- a way to bring the highly personal practice into a more global sphere. The organizers explain:

The class should be held from 11AM - 1PM sharp, local time in each time zone, which will lead to a 24 hour yoga marathon around the world. Devoting our thoughts and energy globally to the human rights issue will generate a powerful impact.

We all know that yoga is good for our strength, balance and flexibility – and some studies show it helps improve the condition of our cardiovascular and respiratory systems. But as every yogi knows, the practice’s benefits for the soul are a central component of what was long viewed as a spiritual endeavor, rather than an athletic one.

Now, a growing body of evidence shows exactly how yoga can help with general mental well-being, as well as assuage the central psychological struggles that many of us face, including compulsive behaviors and insomnia. In most instances, it is yoga's profound effect on stress that provides comfort for a wide variety of problems that count stress and anxiety among their contributing causes.

"The practice of yoga produces a physiological state opposite to that of the flight-or-fight stress response and with that interruption in the stress response, a sense of balance and union between the mind and body can be achieved," wrote Catherine Woodyard of the Department of Health, Exercise Science and Recreation Management at The University of Mississippi in her review of yoga's therapeutic effects in the International Journal of Yoga.

What's more, according to Harvard Medical Center's review of controlled studies on the impact of yoga on stress, anxiety and depression found that a treatment intervention that includes the practice significantly elevates the mood and social functioning of depressed and 'emotionally distressed' people -- including patients who have been hospitalized for major depression, bipolar disorder and even schizophrenia.

One example of how yoga's stress reduction can affect other areas of mental and physical health is in the case of insomnia. A 2004 clinical trial of 20 patients with chronic insomnia undertook a daily yoga practice and reported improved sleep by five measures, including total sleep time, sleep onset delays and sleep efficiency. That may be because yoga helps to calm 'cognitive arousal,' which can be associated with disordered sleep, theorized the study's author, Sat Bir Khalsa, an assistant professor of medicine at Harvard Medical School who has practiced yoga for 35 years.

In a completely different arena, researchers found that people who suffer from eating disorders may be helped by yoga, in conjunction with typical therapy, in part because it helps redirect compulsive behavior.

“Supported by other treatment modalities, yoga can be an effective method for increasing self-awareness, reflection and the ability to self-soothe,” wrote Laura Douglass, a professor at Leslie University in Boston and the author of a study on the use of yoga as treatment with residential and outpatient eating disorder patients.

What's more, in a separate 2010 randomized, controlled study, 54 eating disorder patients were given an eight-week trial of either standard care or standard care with yoga. Researchers found that yoga significantly reduced food preoccupation and lowered scores on the Eating Disorder Examination test.

Yoga is also associated with improved focus for ADHD patients and as a method of treatment for PTSD and other forms of trauma.

So as you contribute your practice to the greater global good this World Yoga Day, it's important to note just how much you're also doing for yourself.