Kurmasana! Is a pose that can be difficult not only to obtain but to look at !as it was for me when I first started ashtanga .Infact I didn't think I'd like to do it ,but when introduced into my daily practice I've become to love it ! it's All repetition and breathing which is a constant during the practice! But this pose is not to be attempted without first being shown by a competent teacher & not without doing the poses leading up to the point you would attempt it as in my primary series ashtanga!! I'm showing this to give an idea of what is achievable in time if your dedicated and the rewards are many if practicedaily!