Go outside

The first thing Vault Human asks your body to do is the oldest thing anyone ever prescribed. Walk.

Ten thousand steps is not ancient wisdom. It is a slogan from a Japanese pedometer company in 1965, chosen because the character for ten thousand looks a little like a person walking. It went largely untested for decades. In 2019 a Harvard team led by I-Min Lee finally did, in about sixteen thousand older women, and found the benefit climbed steeply from around 2,700 steps a day to 4,400, kept rising to about 7,500, and then leveled off. The women near 4,400 had roughly forty percent lower mortality over four years than the women at 2,700. The slogan was a marketing number that happened to land in the right neighborhood.

So the number this month wants is not a target. It is your number, today, written down. Most phones have been counting for you for years without being asked.

Walking is the one movement nearly every body can do, nearly every day, with nothing bought. Twenty minutes at talking pace is about two thousand steps. If you add that to what you already do, you've moved your average by a quarter in one afternoon.

This morning's morning letter said form the habit. This is the habit. It sits beside the scroll on purpose.