1) When u stay up late and burn the midnite oil to mug, it is not gd for ur body becos what u require is ample rest and mugging thru the nite actually lessens the rest u get
2) When u want to relax after mugging for some time, the most likely things u would do is either to find something to eat which would lead to weight gain or juz watch tv or use the computer which requires no physical exertion (Most people dun exercise after being tired from mugging)
3) When u go to places like fast food restaurants like Macs to study, u may have to order some food in order to occupy the table and of coz the food is gonna be eaten by u and so u will gain fats by eating relatively more fast food during the mugging period be4 exams
4) When u want to have more time to mug, u cut down the time spent on other activities and that includes exercising