Every asana works on some or the other prime muscle. We need core strength for Navasana, shoulder and core strength for Sirsasana, Quards for Warriors; but if you are strong willed, generally everything falls in place. Nearly half the class could not get into a Headstand when we joined the YTT. And at the final assessment of our asanas, the entire batch of 17 students did it and some even stayed in the posture for 3 mins.
So did we gain all the strength in a month?
To me it’s the fear of falling that doesn’t let us try challenging postures like the Headstand. In any case, whatever it is that challenges you to the point of hating or fearing it is never going to get any easier for you until you actually face it, and get better at it. And yoga teaches us discipline and persistence without thinking about the prized outcome! (Karma yoga)
So face the challenge and stay focused. Don’t forget, it’s all in the mind!!