Postures are a great entryway to yoga, but there is so much more to yoga than asana.
The Previous Limb -> Niyamas
Etymology
Sanskrit Word: Asana
English Translation: Posture
References to Asana:
Sthira sukhamasanam. Yoga Sutra 2.46
"Asana is a steady, comfortable, posture that can be held without interruption."
Information
It's really important to remember that asana, or the postures that we do in yoga class are the third limb of yoga there are two limbs that come before that. If we haven't set our heart in the right intention and haven't really set an intention to do a spiritual practice of inward reflection, yoga can become more like athletic exercise or something that's really not yoga.
When I go to yoga classes, I think it's really important to consider:
"I know we're doing postures here,
I know there are asanas being practiced,
but are we really practicing yoga?
Are there cues for me to look inwardly or are there cues for me to look outwardly?
Are there cues for me to study myself or are there cues for me to hey look at everybody else?"
Just really thinking about that and what we're really learning in our yoga practice.
