The Fitbit dictates your outfit. If you can't do 10,000 steps, does it really work? | Jess CartnerMorley

Everyone walks everywhere these days. Whenever possible, we walk to work. (Have you seen the price of the trip?) We walk instead of taking the car. (The planet, stupid.) We walk with friends in the park on weekends. (Especially now that everyone has a dog.)

We're all in the grip of our step count. What started as a simple benchmark of cardiovascular activity has become a modern measure of self-esteem. You might not say your prayers before bed, but as long as you walk 10,000 steps, you can rest easy. Walking isn't as sacred as wild swimming, but it still has the power to make you feel pretty smug.

The Fitbit is to the 2020s what the Jimmy Choo Fetto slingback pump (Princess of Wales' favourite, Diana) dates back to the 1990s and Carrie Bradshaw's beloved Manolo Blahnik Hangisi buckled pump to the 2000s. It's the accessory that defines the rest of your outfit. This is the case even if you don't have a real Fitbit, by the way. My step count only runs in my head or on my iPhone's Health app, but it still dictates a lot of what I wear.

Walking is become a lifestyle choice. Taking taxis seems a bit retro these days, even if you can afford it. It seems modern to walk red-cheeked into the pub, closing the Duolingo app when you pull out your AirPods. Falling out of a black cab is a little too Patsy and Edina, in a way. In cities, Google Maps has democratized Knowledge, making urban journeys easier to manage on foot. Meanwhile, a scorching summer has filled our phones with idyllic photos of rural yomps.

On a sunny day, the coastal paths of Cornwall and Norfolk are filled with more than Barbour-clad 20-somethings taking selfies for Insta than retirees in fleece.

But which came first: walking or flats? Did we start wearing flats because we walked more – or did walking become an option once we gave up taxi shoes? The chicken and the egg, but make it fashionable. Years ago, if I was walking to a meeting or a party, I would carry heels in my bag and change into my clothes just before I arrived. It involved jumping on one leg into a doorway, a sight as unsightly as changing on the beach. Which seems crazy now. But back then, being seen in my walking shoes was like going out in an apron or wearing a shower cap. They just weren't mainstream clothing.

For the past 15 years, most "It" shoes have been flats. Even the jazziest, most look-at-me shoes — all those fur-lined loafers and designer sneakers at sky-high prices — have been flat. Features that would once have been found only in Mountain Warehouse's shoe department - wide riptape closures for a comfortable fit, chunky grooved soles for grip - are now de rigueur in the swankiest boutiques. You can have a Carrie Bradshaw level shoe addiction these days and still walk everywhere.

Not only has walking elevated the flat shoe, it has also changed the rest of our wardrobes. The shoulder bag has taken over from the shoulder bag as the standard of the everyday work bag. Shoulder bags these days are made for going out to dinner and feeling chic. And the knee-length pencil skirt, not too long ago an office staple, has almost certainly been jettisoned from your wardrobe, unless you're an American real estate agent.

Walking is more than a way to get from A to B. It's a state of mind. In terms of fashion, it's a good look. So if you can't walk in your outfit, it won't get you very far.