Erchana Murray-Bartlett is incredibly chipper for someone who has just completed her 63rd consecutive daily marathon. When we speak over the phone, she is near Rockhampton in central Queensland, not yet halfway through an attempt to run 6,000km from the tip of Cape York to Melbourne.
Murray-Bartlett hopes to complete 155 marathons in as many days, raising money for the Wilderness Society. She aims to break a world record in the process (106 consecutive marathons, set earlier this year by English woman Kate Jayden).
“I’ve always dreamed of running the length of the country,” she says.
Like Ned Brockmann, who this week finished a 46-day, 4,000km run across Australia, Murray-Bartlett is compelled by a drive to “push the boundaries of my physical capabilities”.
Murray-Bartlett has been racing internationally in marathons for the last several years. Surprisingly, preparing for her cross-country journey required less, not more, training. “The level I was training at for road races was too intense to do what I’m doing, so I actually had to back off,” she says. “I focused more on strength training and I put on a little bit of weight to make sure that at the start line, my body was healthy.” To sustain herself, she is consuming between 5,000 and 6,000 calories a day.
‘Everyone has the genes to be a distance runner’
For the majority of Australians who do not run, attempting even a single marathon – let alone 155 in a row – seems like no small feat. But a lack of physical ability isn’t really a barrier, experts say.
“A lot of people would argue that anyone who’s healthy and active could probably run a marathon,” Prof David Bishop, who leads the skeletal muscle and training research group at Victoria University, says.
“If you go back to our early genetics, basically, everyone has the genes to be a distance runner. Back 50,000 years ago, our survival depended on us being able to walk and jog long distances to be able to get food, and catch animals.”
In the 2009 book Born to Run, the journalist Christopher McDougall details the ability of members of the Rarámuri, an Indigenous group in Mexico, to run distances of up to 300km in a single session, at high speeds and with apparently few injuries. Are there certain physical or psychological characteristics that make ultrarunners like the Rarámuri, or athletes like Murray-Bartlett, better at running long distances than the rest of us?
“There are some people who clearly have a family trait of endurance exercise,” says Dr Adrian Elliot, a physiologist at the University of Adelaide. “Even in an untrained state, they are faster than everybody else.”
There are distinctive physical differences between elite endurance athletes and recreational athletes. “The heart sizes are much larger, the ability to pump blood is a lot bigger, their ability to sustain a high rate of work or energy output for a prolonged period of time is far above everybody else,” Elliot says. These factors mean that aerobic capacity in marathon runners can be 50% greater than in other regularly active people.
“A lot of elite endurance athletes grow up in an environment where they’re doing a high volume of exercise – not necessarily intense – at a very young age. At the same time, they usually reside in areas of moderate to high altitude,” Elliot adds. He cites Kenyan and Ethiopian runners as an example.
Another factor that limits a person’s running ability is their lactate threshold, or lactate inflection point – the maximum exercise intensity an individual can maintain without lactate building up significantly in the bloodstream. It is distinct from “hitting the wall”, the term used to describe the feeling of exhaustion athletes can get when they deplete their body’s reserves of glycogen – a form of glucose that is stored in the muscles and liver.
“Lactate itself is not a waste product, it’s actually a fuel source,” Dr Alan McCubbin, a fellow of Sports Dietitians Australia and a senior teaching fellow at Monash University, says. It is produced by muscles even at rest, but production ramps up during exertion – eventually to a rate that exceeds the body’s ability to use it.
Athletes who are running multi-day or multi-month events are likely not to run at the pace they would run a one-off marathon, McCubbin says, which means that “probably, in most cases, they’re running them quite a bit below that lactate threshold”.
Even a single endurance event, however, exacts a noticeable toll. “There are very few organ systems of the body that are spared during ultra-endurance exercise,” Elliott says.
Immediately after a race of marathon length (42.2km) or farther, some runners have features similar to what is seen in heart disease. “They have blood markers associated with cardiac damage, the heart itself doesn’t look like it’s pumping as well, they develop some fluid accumulation within the heart, or surrounding the heart,” Elliot says.
There are similar effects on other bodily systems. “Liver enzymes associated with liver damage are elevated, we see enzymes associated with muscle damage that are significantly elevated, immune response is heightened … If you scan bones of athletes after an endurance event you see indicators of stress, most frequently in the knees and ankles,” he says.
These changes reverse over days to weeks, but the challenge in Murray-Bartlett’s case is a very limited recovery time. She is completing each of her daily marathons in around four hours, with an average pace between 5m50s and 6 minutes per km. “It’s definitely not my race pace, but it’s a pace that I find I can just cruise along at, and it doesn’t really ever get me out of breath, it just tires me out over time,” she says.
The first month of the journey was “borderline hell”, Murray-Bartlett says. “I got three injuries in my first three weeks – my calf, my quad and my tibia.” Now, she says, she has adjusted to a level of daily fatigue, and the injuries no longer pain her. “I try and get a massage when I’m in every major city … and stretch where I can.”
Mind over matter
For Lucy Bartholomew, a professional Australian ultrarunner and running coach, endurance events require mind over matter – a phenomenon that researchers have also observed. “What draws people to ultrarunning is I think the mental aspect … it’s a very immersive and challenging experience to spend so much time on your own,” the 26-year-old says.
“You’re finding your body’s potential to withstand a considerable amount of movement over a long period of time, and really, the limiting factor is your head,” she says. “I know 100-metre track runners who train more than I do as a 100 mile, 100km specialist.”
Bartholomew ran her first 100km race when she was 15, alongside her 50-year-old father. On the day of her 21st birthday, she won Ultra Trail Australia, the largest trail run in the southern hemisphere.
One physical factor makes it advantageous for Bartholomew when she competes, particularly in hot weather. “I sweat a lot, but I don’t sweat out my salts,” she says. Tests have shown she has low loss of electrolytes through sweating – a trait that varies significantly between endurance runners. “I have never cramped in my life, which is something that a lot of ultra runners tend to [experience].”
Every day of her mammoth attempt, Murray-Bartlett is starting her marathons early to beat the heat, finishing before noon. It leaves her free to spend each afternoon visiting schools and local grassroots conservation groups.
She is aiming to raise $10 for every kilometre she will run in total. “We’ve got almost 500 native animals that are on the endangered list,” she says.
“It’s just something that’s close to my heart, and it gets me up every morning and motivates me to lace up.”