How much recess do your kids get? Should they get more? And Why so much homework?

My third and sixth graders has 20 minutes of recess a day and gym once a week. It does not seem like enough. Here is an interesting article on why kids need more play/recess time.  

5 Reasons Why Kids Should Play in School

I know kids need homework but when my sixth grader has 60-90 minutes standard and sometimes 3 hours.  It is too much.  I sent email to the school today about it.