When I thought about running ultras in 2010, I had never run further than 30 km in a single go. After registering for the Canadian Death Race (CDR), I decided to sign up for the Caballo Blanco ultra-marathon . At the same time, the running world was abuzz with barefoot running. I had always been into barefooting as a way to develop strong blister-free feet and generally strengthen the legs, but as I experimented with barefoot running, I began to think that there was more to running injury free than simply losing the shoes. Together with Amy Barnett, who handled strength and conditioning for Adrenaline Rush Athletics in Calgary we designed a study to test the role core strength played in maintaining a natural running gait and preventing breakdown and injury over distance. The 125K CDR became the laboratory, and I gathered a 13-person study group of experienced endurance athletes to run it solo. 7 went on the running specific core program, 6 trained as they pleased. We tracked athlete’s training in the months leading up to the race, tracked them during the race, and filmed them to analyze their gait before and after the race. Our theory was simple: When the athletes fatigued during the race, their running form would begin to suffer. As their biomechanics changed, the prevalence of discomfort, pain, and injury was expected to increase. A strong core should allow an athlete to maintain their natural running form longer than an athlete with a weaker core and thus slow or reduce discomfort, pain, and injury over long distances.
Unsurprisingly, we found that amongst those runners who finished, all displayed a marked change in their running gait when compared to their pre-race baseline tests. The most significant changes affecting our entire study group were: a wider stance, a reduced heel kick and knee drive, and a tendency to land on a flatter foot. Interestingly, gait characteristics shared with barefoot runners. In addition, muscle/joint pain peaked around 45K into the race. Prior to this, most athletes reported feeling minimal discomfort or pain, and after this, most athletes only experienced a moderate increase in pain, despite having to run an additional 80K.
Pain perception data also showed interesting trends. Pre-race, most athletes felt a level of muscular/joint discomfort, but once the race started, most felt no discomfort. By 46K, the athletes had gained and lost more than 6,000 feet elevation and most were beginning to feel pain in their legs. Pain increased slightly by 67K (three racers DNF’d by this point). By 103K, eight racers remained and five reported pain. At the finish line (125K) only one of eight racers reported no pain. This qualitative assessment is not unusual, as the pre-race jitters may account for the initial discomfort, while the excitement of starting coupled with the endorphin rush may explain why most felt great during the first leg. The effects of racing became noticeable after 46K, which may have significance in terms of distance run, or elevation gained and lost.
Overall, the core-trained athletes did not display an advantage in terms of preventing pain during the race compared to the control group. Instead, factors such as running volume (Greenwood ran the fastest of the study participants and had the highest training volume, running over 150 K/week), geography (terrain and altitude), pre-existing injuries, and distance into the race seem to dictate overall success and injury avoidance in an ultra-marathon such as the CDR. Despite these inconclusive findings, I am still a strong advocate for core strengthening and incorporate it into my normal training routine.