I remember the first time I joined a yoga class and the clothing recommendation was for me to be comfortable.
Do you know how the choice of your clothes can affect the quality of your practice?
So here we go!
***Be comfortable (but):
I also recommend people to put something they feel comfortable in when they ask me what to wear. But students should keep in mind when they are practicing with a teacher they should just covered the body and not HIDE it ;) Super baggy pants and super big shirts make it difficult for the teacher to see how the student is engaging the muscles. If the knees are straight or bend. If the belly is soft or if uddhiyana banddha is engaged. All those points add for the quality of assisting from the teacher to the student.
*If you have too baggy pants (like buddha pants) they are cute but you can step on them and fall. Teacher can not see the engagement of your hamstrings muscles.
*If you have a very large t-shirt on it you block your vision on downward dog also it will be a pain in the @$$ for inversions.
*** For students with minimum clothing:
If you like to practice only with a top, sleeveless and tight t-shirt or tank top and shorts here are some good advices. If you are going to a gentle, yin, restorative etc easy going yoga class you are fine and its ok...maybe you will need a little extra cover for final relaxation in the end because usually the body gets cold. If you are going to a Ashtanga class (Mysore or led) or any dynamic type of hatha yoga class take a towel with you. As we use minimum clothing and we get sweat our skin gets super slippery. Sometimes teachers need a good grip to so some specific adjustments and the towel can be handy. Also for your own comfort you need a towel to keep the mat dry, specially on hot days :)
After all the important thing is too feel good in what you wear. The practice is a bridge to connect us to our inner sensations of the body, mind and spirit so if you get distracted on fixing your bra, your pants are falling and anything else that would take your attention away you need to think in other type of clothing that (1: Do not distract you / (2: It's comfortable/ (3: Will not be an obstacle for your teacher.
Namaste :)
