“When you practice yoga, you are systematically raising the ushna(flow of prana) in the body. If you drink cold water, the ushna will rapidly fall, and this will cause various other reactions. You will become more susceptible to allergic conditions, excess mucus and such things. If you are doing intense asanas and you suddenly drink cold water, you may catch a cold immediately. So never drink water when you are doing asanas.
Slowly, as you practice, as your yoga takes shape within you, if you do any asana, the sweat must pour out from the top of your head – not all over the body. The rest of the body may sweat according to weather conditions, but the main sweating should happen from your head. That means you are directing your energy in the right direction, and the asanas will naturally do that.
Ultimately, you want to become a fountain head of something else, so you first practice with waste water. If you keep working up your ushna, it will naturally take the waste water upward. If your system gets too hot, slow it down with a little bit of shavasana, but never reduce the heat with cold water. ”
There is also the problem of mental distraction, because whenever one feels uncomfortable, instead of simply observing that feeling, one tends to want to get rid of it.The idea is to slowly grow beyond your physical compulsions. Whether it is food, drink, or whatever else, the level of a particular compulsion is different from person to person but the physical is a series of compulsions. The idea is to reduce the compulsions gradually so that one day, if you sit, you become yoga – you are not just practicing yoga”.- article is an excerpt of Sadhguru’s talk given to participants of the Isha Hata Yoga Teacher’s Training Program.