"It's too late to start"

Some readers are past sixty, and the objection they'll have is that this is a book for younger people. Whatever the walking would have done, it needed to be done thirty years ago. The legs are what they are now.

The evidence runs the other way, and it runs the other way most strongly for exactly this reader. Kelly's pooled studies found the largest fall in risk in the lowest band of walking, between people who did almost none and people who did a little, and that shape doesn't reverse with age. Paluch's fifteen cohorts found that for people over sixty the benefit of more steps kept rising until about six to eight thousand a day, lower than the figure for younger adults, and that the steepest part of the curve was at the bottom, among people taking a few thousand steps. A person of sixty-five taking three thousand steps a day is not a person for whom it's too late. They're the person in the studies with the most to gain from the next two thousand, and two thousand steps is a mile, and a mile is the shop.

What is true is that the line moves. The NHS advice for people who haven't been active for a while is to increase gradually, and half a mile and one floor is a fine place to start at any age. It's also true that a body which has been driven everywhere for thirty years will complain for a fortnight, and that the complaint is the body noticing and not the body objecting. Chapter 22 has the cautions, and they apply, and they're cautions about how to start and not reasons not to.

The other thing to say is about the legs at seventy-five and eighty, which chapter 17 touched on. The ability to walk to the shop in later life isn't a fixed allowance that runs out. It's kept by being used and lost by not being, and the people who can still do it at eighty are, for the most part, the people who did it at sixty-five. Starting now is what decides that. The person for whom it's too late is the person who decides it is.

If you're reading this at seventy, the rule is the same and the line is yours. Half a mile, one floor, a coat, the shoes by the door. The shop is where it always was.