THE Spine Challenger is a brutal race. It claws its way along the toughest 174 kilometres of the Pennines, the geological backbone of England, in the dead of winter. It must be completed in 60 hours. Finishers rack up some 5400 metres of ascent, equivalent to climbing Mont Blanc twice.
Participants in 2017 – the fast ones, anyway – would have glimpsed Dom Layfield, an irrepressibly upbeat man in his 40s, pulling away and disappearing into the low clouds and sleet. They let him go, perhaps thinking that this first-timer had underestimated the race’s difficulty and would burn out. They were wrong. After 28 hours of non-stop running and scrambling, he finished first, an hour ahead of his nearest rival, setting a course record.
If exercise is medicine – as we are often told – surely the Spine Challenger is a massive overdose. To complete it takes more than 20 times the 10,000 steps that many of us aspire to each day. Yet hundreds of these ultramarathons have sprung up around the world, and the most prestigious have to turn eager contestants away. At the same time, lifts and escalators are jammed with people who would never consider climbing the stairs. In fact, the average person in the US takes fewer than 5000 steps a day and in the UK it isn’t much more.
As a species, we have a love-hate relationship with exercise. Many people fail to get enough, some seem to get too much. So, what is the correct dose? Or, put another way for the Fitbit generation: how many daily steps should we take to make the most of …