EDIT: synchronicitously, Dr. Sharma wrote this today: http://www.drsharma.ca/adverse-metabolic-effects-of-exercise ....
Every diet-and-health resource from Conventional Wisdom through Atkins through hard-core paleo says you MUST "exercise." Somehow whenever I hear the word "must" it just brings out the contrarian in me.
I'm going to be sixty in about three months. I'm a woman. A woman who lives in a three-story house (plus basement where the laundry facilities are), who does her own housework, who enjoys walking around the Missouri Botanical Garden in all seasons. A woman who lifts her elderly dog every day, who carries around trunks of reenacting equipment regularly.
From an evolutionary point of view, how much "exercise" did my foremothers get that i'm lacking? Probably not much.
Despite the data we see that post-menopausal women benefit from weightlifting, I can't help but suspect that these are people who rarely carry anything heavier than a purse ... however in my sister's case that can be a serious workout. ;-)
Reading The Old Way didn't impress me that this culture's women did an awful lot of sprinting or repetitive heavy-lifting. They walked a lot, carried children and foraged foods back to camp, dug with sticks, .... Looks very similar to me shopping at Costco and other big-boxes, lugging groceries, and house-cleaning. As a matter of fact, me carrying freshly-washed yardage from the washer/dryer to the sewing room is possibly more physically stressful, because i'm going up three flights of stairs with a laundry-basket held in front of me, whereas they're more likely to have used a better-balanced form of carrier.
Want an effective whole-body workout? Try scooping a lot of wet leaves out of the bottom of your swimming pool....
The work of modern every-day living can theoretically burn a lot of energy if you don't hire out the physical stuff to others. It's just the details that change from a primitive lifestyle to ours -- I may not have to visit a spring or well to get my water (except at "Cowboy Town"), but I do get a case of fizzwater at the (far end of the) shop often, lift it multiple times, and carry it from car to kitchen. They dig for tubers, I scrub the bathtub, sinks, showers and toilets. They walk a couple of miles to where the tubers grow, I walk a couple of miles to where the artwork is displayed.
Then there's yard-care and gardening: stoop and walk, squat and pull, diiiiiiig, draw rake and broom, stoop some more, rinse, lather, repeat.
And all the criticism of SITTING that we've been hearing the past couple of years? When I finish those chores I mentioned, I feel like I've earned the privilege of reclining with my feet up.