How much importance of extra activity with regular study?

Extra curricular activities provide student with a chance to practice team work and to develop themselves in other areas. There is some research that shows students who participate in the activities do better in school and have better attendance and higher Grade Point Average. Most of the leaders and successful people will point to the extra curricular activities as helping make them successful. Here is a research [paper that points out some of these factors. http://nces.ed.gov/pubs95/web/95741.asp

I think that the point of elctive classes being requirements in college is to help students become/stay well-rounded. It is cool to be interested and passionate about one particular subject but that doesn't mean that it is healthy to devote all af one's time to only one subject. there is so much to know in the world...