The main problems while studying continuously

The main problems been the first one studying the same material creates boredom the next one is problems with body posture even if we sit in the best posture the straight posture in a chair creates pain or discomfort after sometime say 3 to 4 hours. The problem is the sleepiness or tiredness the get after sometime and at times even after taking food this second problem extremely difficult to control. 

There should be a it is i need to know hindi able to reciprocate again and again and whenever i ask . It is a difficult thing to do though looks very simple. We have to do it again and again. It is boring