You must practise Yoga Asanas for at least 15 minutes in the morning, if you have very little time. On the other hand, if you have enough time, you can practise them for at least one hour. To practise Yoga Asana for 40 to 50 minutes is more than enough. Those who practise both in the morning and evening, should practise them for 40 minutes in the morning and 30 minutes in the evening. It is enough to practise Yog Asan for 30 to 40 minutes in the hot season in places like Delhi where the heat is oppressive in the months of May and June.