And those over 70 who walk an average of 4,500 steps a day have a risk that is 77% lower than those who walk less than 2,000 steps a day.

Actually, the broader conclusion of the study is that if you are retired you should buy some kind of pedometer or step counter, keep track of how much you move, and try to move more.

(Incidentally, you don’t need to spend much on a pedometer either — despite the marketing. I’ve worn for years a wrist pedometer that cost $15—the brand is no longer available on Amazon, but it looks identical to this one, costing $22—and it’s excellent. Long battery life, you can recharge it without a cable, and when I tested the accuracy it beat many of the expensive ones.])

The study was quite limited. It covered 452 participants who wore step counters for three or more days, for 10 or more hours, and then did follow-ups over the next 3.5 years. The average step count per day was 3,500. Some 7.5% had a heart attack or stroke or got heart disease. But among those who took fewer than 2,000 steps per day, that figure was 12%.

Among those who walked about 4,500 steps a day, that was just 3.5%.

The average age of the participants was 78, some 59% were women, and 20% were Black.

The study adds to the growing evidence that exercise, even just walking, are powerful at keeping us younger and healthier.

The caveat with studies like these is that they leave a lot of questions unanswered. That’s inevitable. Just 452 people may not be fully representative of the population. A test run over a few days may not be enough to show long-term trends. And what exactly is being measured?

The common sense conclusion is that the kind of people who tend to walk a lot tend to move a lot and be more active generally. They spend less time on the sofa. That’s good for heart health, especially at older ages. Meanwhile the people who walk very little tend to move very little overall, and they tend to be sedentary and spend a lot of time on the sofa. And that’s bad for heart health.

What gets measured gets managed, as they say, which is why the simplest takeaway from the study is to buy a step counter, wear it every day, and keep track of how much you move around. And just try to get the numbers up.

I programmed my cheapo step counter with a daily steps target of 10,000, and it buzzes and alerts me on days I hit it. If I make it to my 70s maybe I’ll cut that to 5,000.

A $22 gizmo that might help me cut my risk of a heart attack or stroke by nearly 80% sounds like a good deal to me.