Sleep is the best signal for relaxation has to be addressed by the trainer on regular basis. Sleep, as it stimulates the Pineal gland, the important hormone melatonin will bring the Biorhythm. This will enhance the capacity of natural healing processes and immune reactions. At the initial days of teacher training, the bodily strain leads to good sleep. As the second week commence it brings the distractions also into the mind. This will disturb the time given for sleep or quality of sleep. Hence the students usually feel tired which is not because of regular practice but the mental distractions. Few students with eating habits also get sick and face lack of sleep. Hence the trainer has to frequently check the performance of the student and encourage for Prathyahara. With this, the mental distraction towards sense objects and the inwards journey will not be disturbed. This is how the Pineal gland and its biorhythm will be maintained.
Once the student is suffering from lack of sleep or less quality of sleep, encourage for guided meditation more than asana component for 2 to 3 days. Later the normal schedule of asana composition can be followed. Chantings with rhythmic pitch and volume create resonance in the head and its organs. Which usually silence the interactions of brain organs that are thought process. Hence the thoughts reduce. Silencing of mind leads to sleep gently and is the dynamic meditation. This same chanting can be taken in the different way of a dynamic method, which is switching to sound between student groups or individual student. Such dynamic chanting practices will still the mind at present situation and silence the mind effectively.
There are different mantras for the different situation of the classes like opening prayer, closing prayer. These are different and cause a different effect in the brain. This is how mantra chanting that too Sanskrit shlokas have come into Yoga. Japa meditation is also part of Yoga training.