My children's elementary school wants to do away with their recess next year...?

It is a K-5 school. They have been telling the students the reason they are doing away with recesses is because a group of the students (currently in 4rd grade) are misbehaving. They will do away with recess for next year's 5th graders. While I know they can do this, is it really in the best interest of the children? At the age of 10 and 11 it is so good for them to get outside and burn off energy! Currently they have a 20 minutes recess in the morning and afternoon and a 30 minute recess at lunch.