Which is totally fine, as far as I am concerned. If doing this practice for the sole purpose of getting a tight ass or beach body (or whatever ass/body) works for you and rocks your boat, more power to you. After all, didn't this particular South Indian gentleman, one Sri K. Pattabhi Jois, famously declare, "Do your practice, and all is coming"? The "all" here, I suppose, should include tight asses and beach bodies, don't you think?
But I suspect that many people out there may look at the tight-ass-motivated Ashtangi and shake their heads in disapproval, saying that our Ashtangi here should be aspiring to more exalted things. After all, if our friend here has "advanced" to second or even third series, shouldn't he or she have totally transcended any ass considerations, and be striving for higher, less body-oriented goals?
What might be these goals be? Energetic openings might be one possible candidate. The trouble with energetic openings is that, for one, they are not things that you can necessarily will or intend to occur at particular times or places in the practice (then again, is there anything in the practice--or indeed, in life--that works this way?). For another, according to Owl, it is quite possible that:
"most westerners intuitively slow down their own transformation by half-assing the concentration, relaxation, diet or drste. At first, some rajas or tamas intake (emotional, dietary, mental) may act as insulation."
As somebody who half-asses these things in more ways than I can count (or am conscious of), I think I can understand at least some of what Owl is saying here, even if I may not fully appreciate what my half-assing is preventing me from experiencing (or insulating me from, if one wants to put a more positive spin on it... it's very much a matter of perspective here, I suppose :-)). If many other Ashtangis in the west are in the same position as me, then it looks like if one is to have any chance of experiencing any kind of energetic opening, one would need to eliminate those things in one's concentration, relaxation, diet or drste that are causing one to half-ass one's practice. Which is possible, I suppose, but definitely no mean feat.
Long story short: Striving for/aspiring to an energetic opening is probably counter-productive, and would probably lead to a lot of unnecessary suffering from unfulfilled expectations.
So striving for/aspiring towards energetic openings as an explicit goal of practice is out of the picture. What other possible candidate/s is/are left? What about Samadhi, that holiest of holy grails of yoga practice? After all, if one is going to forego tight-ass considerations as a motivation for practice, one may as well strive for the highest possible yogic goal. But samadhi turns out to be a little more complicated than might be apparent at first glance. Yoga Sutra 1.17 describes four forms of Sampragnata or distinguished samadhi:
is accompanied by inquiry
into its four forms
analytical thinking about an object,
meditative insights on thoughts,
reflections into the nature of bliss,
and inquiry into one’s essential purity."
translated by M. Stiles
According to Swami Shyam, these four forms of samadhi culminate in an inquiry into bliss during which there is an awareness of peace and joy, and a lack of awareness of words, meanings, time, space. At the same time, there is also an awareness of the fluctuations of asmi, the source of ahamkara, or ego.
Commenting on this passage, Swami Satchindananda further cautions that the practice of samprajnata samadhi must be pure and selfless or else the practioner or sadhaka will abuse their new found powers and abilities.
I find Satchindananda's words here very interesting: If one does not practice samadhi with pure and selfless intention, one will abuse one's newfound powers in this area. This means that it is possible for one to attain samadhi while having impure intentions and being selfish. In other words, it is possible to attain samadhi and still be a total asshole! Which means that one can be a self-realized asshole!
Interesting... But if one is going to make all these efforts to attain samadhi and still remain the asshole one was, why bother? Why not just stick with tight asses and beach bodies? At least one would have less things to worry about that way.
Maybe I have discovered a certain paradox; let's call this the paradox of samadhi: One starts out the yoga practice being an average asshole. In order to overcome this asshole nature, one embarks on the practice of yoga, aspires to and eventually attains samadhi. However, if Satchidananda is right, then it is quite possible that one could still be an asshole after attaining samadhi. A samadhied asshole, but an asshole no less.
Or maybe the goal of yoga practice isn't actually to stop being an asshole, in the first place. Maybe it's just this: Do your practice, and all is coming (and even if you are an asshole, it is still coming...). Shows what I know, right? :-)