When two-time Olympic marathoner Des Linden steps onto the course at this year’s New York City Marathon, she won’t be alone. In addition to the more than 50,000 other runners competing with her, she will be accompanied by a “digital twin” of her heart.
Not that she’ll be able to see it during the race. As the name suggests, it’s a virtual creation, making it against the rules for her to access it during competition. But, as she has hinted on her popular running podcast, Nobody Asked Us (co-hosted with fellow Olympian Kara Goucher), it will be on display during the television coverage of the event, allowing viewers to see how her heart responds to both the challenges of the marathon and the strategic and tactical decisions she makes along the way.
On first impression, a digital twin sounds like nothing more than a computer model, akin to what meteorologists have been doing for decades in order to make ever-more-accurate weather forecasts.
But it’s a lot more than that says Brian Purvis, manager of a digital lab at business technology provider (and event sponsor) TCS in Cincinnati, Ohio. “It’s not just a virtual representation,” he says. “It adds in real-world live information on top of that.”
Linden’s heart isn’t the only one being digitally twinned. TCS is already working with a dozen other runners, including four Indigenous Australians targeting the 2025 Sydney Marathon.
The first step in creating Linden’s digital twin was taking an MRI image of her heart to map its structure, plus an EKG to determine its functioning. Purvis’s team then equipped her with such instruments as a heart-rate monitor and blood-oxygen sensor to monitor how her heart functioned during three months of training at various intensities, workout styles, and durations.
This was then used to train an AI to not only replicate what was going on in Linden’s heart during all those hours of data collection, but to predict what might happen under an even wider range of situations—such as during a race. “That’s the ultimate goal,” Purvis told Cosmos, “being able to leverage this data to train the AI model for predicting different scenarios.”
Already he and colleague Raja Shan have learned interesting things about how decades of elite-level training affect the heart. For example, Linden’s heart not only pumps blood much more efficiently than the average heart, but it recovers unusual rapidly from exertional surges.
“Her body immediately settles back down,” Purvis says. “A lot of that’s because she’s trained her body so well over the last 20 years to allow her heart to expand and grow, but at the same time is able to rest and relax quickly. That was one the neater insights we were able to gain.”
They’ve also discovered that unlike most people’s hearts, which only manage to put half of their power into pumping blood (the rest goes into waste heat), Linden’s is 80 percent efficient—a possible reason why hers can also pump 40 percent more blood than average.
For elite athletes, all of this offers new ways of optimizing both training and racing. For sports fans, it opens the door to a new round of jaw-dropping performances expanding the boundaries of what’s considered humanly possible.
It also offers the prospect of more effective training for in-the-pack marathoners or 5K runners. And it isn’t just the heart for which it can be done. Next up, Purvis says, is to create digital twins of muscles and bones, in order to understand how these affect performance.
Sports isn’t the only possible use. Digital heart technology has the ability to warn people with heart disease that they are pushing their boundaries, says Shan, and even, when necessary, to advise surgeons about what is needed.
Purvis adds that it can also be applied to other parts of the body, such as the nasal cavity, to make inhaler-based medications more efficient. “Now,” he says, “it’s all very standardized. You take a spray and it goes in your nose, and you don’t think about how it hits different receptors. But everyone’s nasal cavity is slightly different. You can look at aerodynamics and flow, and understand what part of the nose is actually going to get the right amount of medicine, which will then allow you to do mass customization of personalized medicine.”
Shan notes that the technology could also be useful for anything from drug development to safety testing of food additives. With a fully developed biological twin, he says, it might be possible to avoid the need for both animal trials and human testing, “or at least reduce it to the max.”
This weekend, however, all eyes will be on Linden and her digital heart. Not that she’s likely to win the NYC Marathon. At age 41, she will be up against far younger runners. But there are such things as masters (age 40+) records, and if all goes well, she’s a likely contender for one of those.
The heart of an elite athlete
