Who Can Benefit From More Challenging Yogasanas?
Before thinking about a physical posture, let us be reminded that Yoga is the science about the mind (while, for ex., Ayurveda is all about the body, but not vise versa.)
So, one of the main function of any asana (posture) is to access the mind through being present to the movement of the gross level of our being-the body. Be present to the inner atmosphere, mind reactivity, rigidity or acceptance and flow without any judgment. Another function of any asana is the breath. In Yoga we say that most pranayama (conscious breath extension) happens through the movement. Meaning we breathe through the blockages: bodily or mental as well as emotional sensations.
So, as we think of yoga practice, we should always think of the effect: What the effect? Where the effect happens? And on Whom?
Different people have different constitutions and need different effects on their body, breath and mind.
But imagine, you are a long time practitioner, rather healthy and fit and in order to feel it deeper at all your levels with the time you may probably need to deepen your physical asanas as well. Having said that I mean, as we change and develop, so as our practice. To feel the same twist in the lower abdomen in 5years from now, you may probably need to modify and experiment with more challenging twisting poses. To deepen your meditation practice you may go from 6 breaths in a stay pose to 12 long breaths with extra poses. Deepening your practice is a practice in itself. As a therapist I don't believe in jumping into a challenge for the sake of losing weight or making a beautiful picture. Even though it may seem like a valid effect, it will most probably be a good exercise, but not Yoga.
There is still lots of poses that I don't attempt on trying for they do not serve my practice, or my individual peculiarities.
The wisdom of Yoga always remains the same: it should bring you back to your essence, not to your best split!