When Conner Mantz broke Khalid Khannouchi's North American marathon record in Chicago last October with 2:04:43, the most striking part was how easily he seemed to absorb it. He told Race Results Weekly this week that it was the best he had ever felt after a marathon, and that the run he did the next day felt like the aftermath of a hard long effort rather than a race. In hindsight he reads that as the problem rather than the achievement: it gave him, in his words, a false sense of how recovered he was.
What followed was two sacral stress fractures and the better part of six months out. The 29-year-old missed January's World Athletics Cross Country Championships in Tallahassee, where he had hoped to contend for a medal, and April's Boston Marathon. He was not able to run on land again until mid-May. His own account of the cause is unusually direct: mileage brought up too quickly, a pacing job at his wife's marathon in November, and, as he put it, overtraining and overuse on top of a body that had not finished recovering.
It is the second injury rather than the first that carries the lesson. By his account he was doing the rehabilitation work, sleeping properly, eating well and holding back in training, and the sacrum broke anyway. That is the pattern that should interest anyone managing bone stress injuries: once the tissue has been compromised, the habits that keep a healthy athlete healthy are not necessarily enough, and the total mechanical load has to come down rather than simply be better organised. Mantz and his coach, Ed Eyestone, concluded that something structural in the week had to change.
The change was not fewer miles but lighter ones. Mantz now runs twice a week on a treadmill fitted with a LEVER body-weight-support system, taking roughly 15 per cent of his weight off the legs on recovery days. It is a way of keeping the aerobic stimulus and the running-specific movement while cutting the load through the pelvis on precisely the runs that contribute least to fitness and most to accumulated stress. He says things only began to feel normal again two or three weeks ago. His first race back, the Falmouth Road Race on 16 August, produced 31:19 for fourth: he could hold the pace, he said, but could not respond when the race moved.
That is the honest context for Sunday's World Athletics Half Marathon Championships in Copenhagen, where he estimates he is in roughly 59-minute shape on a flat course that may yet be windy. A year ago he would have talked about the podium, which only one American man has reached, Dathan Ritzenhein taking bronze in Birmingham in 2009. He is not talking about it now, and is instead framing the race as competition rather than a workout on the way to the New York City Marathon on 1 November. For an athlete rebuilding from two bone stress injuries, being able to race at all in September is the result that matters.