Whenever I visit a school I try to learn as much as possible, always making it a point to ask students how they spend their day. I'm interested for a few reasons, including discovering how much physical activity they get. While my "research" is anecdotal, there's plenty of evidence (besides our waistlines) that shows we get less exercise than we used to.
we might "know" exercise is good for our bodies, and we may even "know" exercise improves our mood,
there's mounting evidence showing exercise as being good for brains, especially young, developing brains.
So, when I see kids, parents and teachers push back against
reducing gym time,
increasing homework loads, I say keep pushing.
Less can be more when it means more time for play and getting our heart rates up. Less homework, less rote learning and fewer organized activities can lead to healthier and more creative kids, who also happen to test better.
Consider checking out
Spark, a book on the science of exercise and the brain. Dr. Ratey's blog