I should be pretty clued up on in-race nutrition. I’ve twice run the infamous Marathon des Sables, raced across mountain ranges, sweated through Amazon jungles and clocked countless road marathons. And, unsurprisingly, there have been moments when my body definitely needed an extra kick. But I have a confession: I had never fully understood the intricacies of in-race fuelling. Not knowing exactly what my body needed (and when), put off by the taste and what I’ll delicately call some ‘digestive incidents’, bamboozled by the array of gels, powders and bars on the market, I had stumbled through, trial and error – with an emphasis on the latter.