I had a perfectly lovely date with a Turkish/Italian man last night, who informed me of an awesome dog breed in Turkey called the Kangal (http://en.wikipedia.org/wiki/Kangal_Dog). He mentioned that this huge dog needs something like 7 miles per day of roaming to keep fit and happy, so best to keep them in the countryside where they can go out freely.
This got me thinking whether humans have a similar number for how much walking to do per day. I say walking and not just exercise because I imagine our ancient ancestors spent most of their time walking and not deadlifting, etc. I am wondering how close this 10,000 steps per day fad comes to our optimal walking need. At an average stride length for a man of 2.5 feet, 10,000 steps covers 25,000 feet, or just under 5 miles. This seems really reasonable, especially considering that walking (at 150 lbs) burns about 100 cal/mile, this is a caloric burn of about 500/day. Over a week this equates to 3500 calories burned, saving you roughly a pound of bodyweight from being put on each week.
I think walking also stimulates nerve endings in the feet, acupressure-style, which can stimulate healing processes in other parts the body. Walking without a heavy pack on also helps build core strength and posture support, and good posture can alleviate everything from sinus drip to migraine headaches and back pain.
I mention all this because I used to hate walking. I considered it an inefficient waste of time, and boring. I walked 12 miles on Sunday (with a dog, less boring!), much longer than I’ve walked in a long while, and my body feels so good! I’ve walked/hiked more in the past eight months than I probably have my whole life, and I am in the best shape of my life. Coincidence? I think not.
My guess is I probably do 3-5 miles when I go out, some of that jogging/sprinting. So the numbers are lining up pretty well. Imagine if everyone did this, we’d meet more of our neighbors and all be better looking and more healthy!