Ten thousand is a likable number. It’s rotund and cheerful, both aspirational and accessible. Ten thousand is like the serious but fun kid who sat near you in high school chemistry — not as goofy as 3,850 in the back row, or as aloof and vain as 100,000 up front.

Ten thousand is also how many steps a day you’re told to take if you want to maintain good health. It’s been prescribed like a multivitamin, or those eight, eight-ounce glasses of water we were once instructed to consume every day to stay hydrated and rosy.

And it’s definitely a thing. The American Heart Association recommends 10,000 steps every day. The Kaiser Permanente health group administers its own program, “designed to help you gradually increase your physical activity level and work toward a goal of walking 10,000 steps each day.” If you buy a FitBit, one of the new generation… More…