some science behind the goodness of Yoga

So I've been working on a report for work, and thought I'd share goodness of Yoga on mental and physical health- from a scientific point of view.I've taken bits of information from a few journal articles and condensed it to something short, and hopefully, easy to understand.

So when you are stressed out.. (let's say it's work, or you had a fight with someone, or you've seen a horrible photo of yourself on FB and can't get through to your friend to remove it ha ha ha.)... the fight or flight response is activated.

What is the fight or flight response? 

Basically, we have a part in the human body known as the hypothalamus. So the hypothalamus activates 2 systems in order to produce the fight-or-flight response. These two systems are known as the SYMPATHETIC nervous system and the ADRENAL-CORTICAL system. Both of these initiate reactions in the body and bloodstream, resulting in you feeling tense, alert, blood pressure and heart rate go up..

So imagine you are a girl (such as me) and you get hold of your parent's credit card (hypothalamus) and decide to do a little online shopping. So you get a little carried away oh wow ASOS woohoo Forever21 yeah.. okay and you purchase whatever you want and pay by credit. Soon enough stuff gets mailed  home - YEAH ALRIGHT I HAVE MY CLOTHES (you're thinking), yeah and then MUM (sympathetic nervous system)  and DAD ( adrenal-cortical system) see what you've done and realize, hey did you use my credit to buy all this? Yeah then they give you a piece of their mind ( firing at you, telling you to like BEHAVE). Yeah and now, how do you feel? Tense? Upset? Heart rate up? Blood pressure? Yesssss so now you kinda get the drift? :)

haha anwayyyyyyy, so when this happens, when the body is stimulated by stressors,  a cascade of psychological and physiological effects take place within the body. When this sort of activation of the fight or flight response happens frequently, alot of energy is used to combat the stressor. Inflammation within the body occurs and immunity goes down. When immunity goes down, we open ourselves to illness/disease. We basically create an internal environment which is more susceptible to falling ill.  Over time, repeated activation of the fight or flight response from constant firing of the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system (SNS), leads to high stress in the body internally, and dysregulation of the system.

Now when we practice Yoga (Which is not just comprised of postures, but also breathing techniques), what happens is.. an activation of the parasympathetic response via vagal nerve stimulation. Yoga techniques down-regulate the HPA axis and SNS, having an immediate quieting effect on the SNS=HPA axis. 

So basically, it reduces the typical fight or flight response and it promotes a more relaxing effect, leaving those who practice yoga feeling rested, experiencing elevated mood states, and reducing stress levels. Overall, there is less inflammation and immunity levels don't go down as it ordinarily would. Leaving the practitioner LESS susceptible to illness/disease.