Well look, it's somewhat difficult for me to evaluate that sort of thing without direct observation but it's important not to overdo things if you are out of shape. I haven't any relevant basis for determining that, but typically Yoga is a relaxation discipline and if you place yourself in positions where blood pressure can be altered it can certainly trigger a physiological response to restore balance.

Never look upon these activities as a direct 1:1 relationship with regard to stress. While exertion in the way of regimented exercise or meditation is designed to reduce stress, the presence of anxiety and associated symptoms can nevertheless invoke a response. This is particularly true if you become focused and worried about the presence of palpitations or other symptoms that may be occuring contrary to beliefs or expectations.

Many people expect to relieve anxiety and stress through these sort of programs and it's important to realize that participation doesn't necessarily equate the activity with stress reduction. There is an underlying problem with anxiety in your case and it simply won't abate because you're practicing Yoga.

Does that make sense? Let's use an example to illustrate further; Let's suppose you're having difficulty finding the right evening gown for a night out and so you attend a fashion show in the hopes of solving  the problem. Now at first glance, that would be a reasonable solution but to make it relevant here, we also learn that you have a fear of attending social functions and no gown seems good enough to try and compensate for the insecurity that you experience and thus, no selection can be made because you begin scrutinizing each and every gown on the basis of how you will be perceived and accepted in order to avoid rejection. See?

So in the case here, we have an underlying problem that we reasonably presume can be resolved through stress reduction and when you begin experiencing anxiety symptoms in the presence of an activity throught sure to remove such features, you become confused and frustrated. This response sets in motion fear due the fact that it seems even activities designed to reduce symptoms in your opinion fail to meet with success.

You must discover the underlying problem in order for Yoga to become effective. None of these programs or potions that marketers dream up and impose upon unsuspecting folks just wanting help for their anxiety will ever actually reduce anxiety by addressing the underlying problem. It's just not possible and yet, people consistently either try and make this presumption or are led to believe it by those wishing to benefit from your circumstances.

The really good news is that you can be helped, but you must first be willing to explore your life to determine what has set in motion and is responsible for your anxiety disorder. Once you are armed with this knowledge, you can begin reducing factors that exacerbate symptoms and before you know it, you'll truly be on the road to feeling better. Many patients are entirely unaware of the underlying problem that has created the anxiety disorder because it doesn't necessarily take exposure to something horribly traumatic, but rather the perception at the time of the precipitating event. Let's use another example to illustrate what I mean here;

If you are walking through town and make a turn off of the sidewalk to cross the street and a streetcar appears to miss you by only inches and sounds it horn, you could conceivably interpret the outcome several ways. You could realize that the car was many feet away and an over-reaction was made by the driver of the streetcar, causing you to generally ignore the experience as anything of dire consequence.

Alternatively, you could have perceived the event to be a brush with death and from that point forward have great challenge in crossing the street, particularly if you have to do so as part of a daily regimen.

Now let's take it a step further. An event like that described above takes place which initially invoked a great deal of difficulty is rationalized in a manner that permits you to function with reasonable comfort in order to get through your day. Layers upon layers of events diffuse the trauma and your memory of the event is less than accurate. When asked how you feel about it today, you shrug your shoulders and say "I don't think I'm particularly bothered by crossing the street, I suppose." Well, you can physically cross the street because you have to in order to make it through your day but in your mind the apprehension has grown to proportions that create tension and emotional discomfort that over time, has become dissociated from the original event. So when asked, you respond "I can't understand why my heart races and I feel so ill all of the time. I mean, I don't FEEL anxious."

And so to deal with the anxiety, persons afflicted often begin experiencing the need to count things, keep their house immaculate by over-cleansing, become germaphobic, have racing thoughts, insecurity about things in general, become less social, etc. Most of all, the symptoms of anxiety become physical and the symptoms reinforce the insecurity. It causes a down-spiral of general outlook and search for answers to unidentifiable problems.

See how complex it can become? The way back to yourself is through careful reflection and assistance in discovering the underlying problem. You'll be fine.

Best regards and Good Health