"It felt like we were marching through a battlefield. People were gasping for breath and shouting for help. Lots didn't make it to the end, either collapsing from exhaustion or unable to take the pain any longer."
That is how one friend dramatically described the 24-hour, 100km charity walk from London to Brighton. What was I thinking when I signed up? But since making that rash decision last November, I've had little choice but to lace up my first ever pair of walking boots and take to the streets of London. It has been a refreshing – and blistering – experience.
A few years ago, walking was a hot topic, with charities and media commentators encouraging us to get a pedometer and walk 10,000 steps a day. But it seems we didn't listen: according to the historian Joe Moran, walking has declined by 25% in the past quarter of a century in the UK; a YouGov poll recently revealed that as many as a quarter of British adults walk for an hour or less a week – and that includes getting to the door of your car. Two-thirds of adults in the UK don't do nearly enough physical activity. The result is clear: sedentary Britain is facing a public health crisis.
At a recent TED lecture, the author Nilofer Merchant said sitting is the "new smoking of our generation". The phrase has been picked up by public health academics and experts, who warn of a worldwide pandemic of inactivity. Even going to the gym in the evening isn't enough to offset nine hours of sitting still in the office, according to studies. Walking needs to be part of everyday life – your commute to work, your journey home, your visit to the shops, your lunch break, and even the way you work.