As an early childhood professional and a mother of two, I am saddened that schools would need a law to require them to provide recess time for children. I have 3 major reasons for believing that recess is desperately needed in schools: 1) physical fitness, 2) social development, and 3) for lack of a better word--sanity.
1) Physical fitness. We are all bombarded with news of how obesity is taking over our nation and how our children's lives will be shortened by a lack of physical fitness; news on how children spend their time on video games rather than running around outside. Why then would we want to take one more step to remove their opportunities for physical play? (They can't opt for video games at school recess.) Granted, not every child will be physically active during every recess, but a quick perusal of any playground will show a lot of physical activity.
2) Social development. There is a book that describes how the author learned everything he really needed to know in Kindergarten. A similar book could be written about how everything you need to know about living in a society can be learned on the playground. Children don't learn a lot about how to deal with each other when they are sitting at their desks doing school work. On a playground, children learn to share, compromise and deal with disappointment.
3) Sanity. How many of us, as adults, could spend 7 hours of each day with only a quick lunch break? That is what we are sometimes now asking our children to do. We ask them to sit at a desk and pay attention to their teacher for a little over 3 hours, give them 30-40 minutes for lunch (which sometimes barely gives them time to eat their food and, p.s., some schools do not allow talking during this time) and then sit them back at their desk for another 3 hours plus. I couldn't do that, nor would I want my children to do it.
Think back to your recess times--the chance to run off a little energy, breathe some fresh air, interact with your friends. Personally, I looked forward to every recess. Let's make sure our future generations can do the same.