Claire Squires never stood a chance after taking amphetamine in London Marathon On Wednesday, at Southwark coroner's court, we learned more about how a healthy, fit, prepared runner came to meet such an awful end during the country's biggest mass participation sporting event. Prof William McKenna of the University College London hospitals trust, who conducted her autopsy, said he found "significant levels" of an amphetamine-like substance in her blood. And her boyfriend Simon van Herrewege revealed to the court how that might have come about. Ahead of the race she had bought a carton of a drink supplement called Jack3d on the internet. "Claire was always in the gym and this stuff was being widely talked about there," he said. He added that she had told him she was going to mix a couple of spoons-full of it into her water bottle and would take it if she was struggling in the latter stages of the race. It would help her to get over the wall, she told him. Give her the legs for the last push. Unbeknownst to her, one of the ingredients of Jack3D is the amphetamine DMAA. And it was that, taken at the conclusion of a highly strenuous sporting event, that pushed her heart rate to an unsustainable level. The thing she thought was going to give her a little boost over the line was the very last thing she should have taken at that point. No professional distance runner would touch anything like Jack3D. And not just because it is on the athlete's extensive list of proscribed substances. There is a reason some substances are banned beyond the artificial help they give. Especially amphetamines. Ever since Tommy Simpson died on the Tour de France after taking a couple of blue pills, the mix of such drugs and endurance sport has been known to be a lethal cocktail. But Claire Squires would have had no idea what was inside Jack3D, what gave it its kick. As far as she was concerned, this was something wholly benevolent, a legal product that was going to be a bit more useful than eating a banana. She bought it innocently and openly, on the recommendation of other gym users. And it cost her life. The thing is she would not have been alone in that race. Right across the ranks of fun runners, everyone is looking for something that might gift them an extra few seconds off their time, or make their legs ache a little less. Recommendations spill across the internet of what you should wear, what you should eat, what you should drink. This is not doping; everyone is just looking for something to make the difference. Why, even Lance Armstrong, the man who won the world's greatest cycle race seven times, claimed in self-justification for his drug regime that it is impossible to compete in such events without help. Armstrong's help may have been as illegal as Claire Squires's was legal, but it was less dangerous than hers in this crucial respect: it was conducted under medical supervision. Thanks to a complicit doctor, he was informed precisely what it was he was taking and told when to take it. And more to the point, when not to. That was how, he said, he could level the playing field. And in terms of his health if not his reputation or wealth, he has clearly got away with it. The stimuli which propelled him round France at such speed do not appear to have had any obvious lasting side effects. Unlike Armstrong, Claire Squires did nothing underhand. She acted out of ignorance, duped by an industry which makes reckless promises on what it can deliver. Unaware of what she was doing, she suffered the terrible misfortune of having a metabolism unable to cope at that point in the race with the sudden stimulus that kicked in from the drink. By complete coincidence, in August 2012, five months before the verdict on her death was announced, the medical regulator MHRA recommended products containing DMAA be removed from sale as they pose "potential risks to public safety." Runners on this year's marathon will not be able to buy Jack3D. Which, tragically, is way too late for Claire Squires.