I f you’re running the London Marathon this weekend , chances are you’ve been training for months to build up the fitness and resilience needed to see you through 26.2 miles. The last thing you need is something unexpected to undermine all your hard work at the last minute . The problem is, there are a few pitfalls worth sidestepping as you approach the start line. Anthony Fletcher, founder of running community and coaching platform OneTrack Club , is here to help you do just that. Below, he details the common mistakes he sees people make over the marathon weekend , as well as revealing how to avoid them. His tips can help you reach the finish line without any hiccups. Stick with your prep plan on race day “It’s a cliché, but we still see people do it every year: don’t do something new on race day,” Fletcher says.…