Unlike many other physical education activities, yoga has a warm-up built into it's practice.  By starting with standing poses and using a lower intensity, students are able to gradually warm-up their bodies.  As the skill level of the student becomes greater, more intricate poses can be used as a warm up.  The basic principles of warm up, however, should not be forgotten.  They include raising core temperature, stretching the muscles and preparing the student for the main body of the lesson.  Yoga warm ups should also place an emphasis on breathing techniques.  Since breathing is one of the important principles of yoga, and a warm up is supposed to prepare the student for the activity, highlighting the importance of proper breathing is very important.  Since yoga is a very unique exercise in that in it is very personal, it is difficult to come up with a diverse number of possible warm ups.  Most yoga warm ups will be encorporated into the main body of the lesson by using dynamic poses.  Possible poses used for warmup can include: Tadasana, Vrksasana, Triksonasana and Virabhadrasana II.  In community yoga it is possible to have a warm up entirely composed of breathing when it is done in a steamed atmosphere (called 'bikrams yoga').  This type of warm up achieves all the goals of a typical warm up without movement as it warms the muscles and body entirely and also cognitively prepares the student for the activity.