Walking and Sleeping

Another benefit of frequent walking that I've found is better sleep.  I see all these ads for insomnia prescription drugs on tv, and I can't help but wonder if exercise would solve this problem for many people.  It seems the body needs a minimum amount of activity, say 30 minutes each day, to set up proper sleep.

Hunter-gatherers exercised every day.  We should to if we want our bodies to function optimally.