When Chrysti Thompson fulfilled a lifetime ambition by signing up for the London Marathon; her husband Leighton thought he would do too – despite having no running experience. From gradual preparation of informal park runs to building to 10ks and half marathons, his first race will be the country’s most iconic running event on April 28. “I don’t mess around,” he joked. have been training together since the autumn. Chrysti who has run all her adult life is rather cross…