How Yoga Can Boost Your Immune System

Fall is here! The leaves are changing colors, the air is cooler, the nights are getting longer, and flu season is back. The first signs of a cold began to linger in my sinuses and throat this week, and although I welcome fall with open arms I am less excited about the sniffles, sneezes, and coughs that it brings with  it. Searching for some preventative measures I could take to nip this cold in the bud, I stumbled on this article by Anna Roberts McMurray (http://www.active.com/fitness/Articles/How-Yoga-Can-Boost-Your-Immune-System.htm), which is about how yoga can boost your immune system.
McMurray discusses four different ways that yoga can reduce our susceptibility to colds and viruses. First, yoga helps diminish the psychological stress that comes on full force in the fall as we are bombarded with exams, work, and holiday planning. By lowering our stress hormone levels and relaxing the nervous system, yoga tells our bodies to settle down and stop attacking the foreign bodies in our nasal passages (which we expel on our own by sneezing once a day).  She writes that "when the immune system backs off, inflammation and mucus decreases and symptoms diminish." Second, yoga can boost the health of our respiratory system, which is a chief player in housing and attacking cold-causing bacteria. According to McMurray, "breathing technique and asana (posture) help improve the mechanical efficiency of our lungs by conditioning the repertory tract that increase the elasticity and strength of the whole lung." This increased strength helps fight off infection more effectively. Third, yoga aids our body in clearing out the natural toxins and mucus that builds up in our organs. Yoga also stimulates breakdowns of these toxins in our body by supplying fresh blood and oxygen to different organs. The different asanas we assume during yoga helps tone, massage, and stimulate certain organs which increases their functionality and ability to fight off infections. Finally, the fluidity and movement of yoga lubricates and strengthens our joints and muscles, which can become stiff and uncomfortable in the cold, dry weather that comes with autumn and winter. 
McMurray prescribes yoga participants to pursue movements that open the chest and to breath deeply and fully into each pose. She suggests such asanas as pranayama, bow, camel, cobra, and half moon for pursuing a revitalized and stimulated immune system. 
I, personally, found this article helpful and informative, especially as my own levels of stress, sleep deprivation, and muscle tension begin to escalate with approaching exams, projects, holidays, and papers looming in the near future.