Winter 2019
U of M soccer forward April Bockin. Illustration by Jacey. Photo courtesy of U of M Athletics
Cover Story

Building a better athlete


April Bockin lies motionless on the light blue table of the DXA scanner in the U’s Human Performance Teaching Laboratory at 3M Arena at Mariucci. The machine’s cream-colored arm hovers above her. After emitting what sounds like a Morse code message, the table and arm slowly pull away from each other, then stop and switch directions. They repeat this pattern for the next three minutes as they pass over the body of the U of M’s All-American soccer forward.

As the arm moves, it shoots out a low dose of radiation to gather information about the bones, muscles, and fat in various regions of Bockin’s body. Software developed at the U analyzes the data, pointing out specifics that could affect her performance: Her right leg—her kicking leg—has more lean muscle than her left, for example. 

Bockin’s scan will become part of a database of Division 1 women soccer players that will help researchers learn more about the ideal body composition for different positions and how players’ bodies change during the season. It’s part of a project called Dexalytics that has its roots in the U’s College of Education and Human Development (CEHD). 

Bockin, recipient of the Elizabeth Lyle Robbie scholarship for women soccer players, hopes to play professionally after graduating this spring. She plans to share the findings from her scan with her strength and conditioning coach in order to find out if she should train differently to be more effective on the field. 

“The more you know about your body and yourself, the better you can be,” she says. “Scanning shows you things I don’t think anyone could tell you.” 


Commonly used for measuring bone mineral density in adults, DXA (short for dual-energy X-ray absorptiometry) is considered the gold standard for evaluating body composition—specifically fat, bone, and lean mass. Don Dengel, Henry L. Taylor-Arthur S. Leon Professor in Exercise Science and Health Enhancement in the U’s School of Kinesiology, was among the first to use it to study effects of abdominal obesity on insulin sensitivity in adults in the 1990s. In 2000, he joined CEHD and began doing similar work with children. “We’ve had a lot of experience with DXA and different populations,” he says. 

So when a rep from GE, which makes DXA scanners, called in 2011 and asked if Dengel would meet with the Green Bay Packers to help them figure out what they could learn from DXA data, he was intrigued. “They had 950 scans on players, potential draft choices, free agents, and potential trades,” says Dengel, who had previously worked with collegiate and Olympic athletes. 

How DXA works
Dual-energy X-ray absorptiometry (DXA) uses a full-body scanner to measure bone, fat, and lean tissue. 

The scanner has a movable arm that shoots low-dose X-ray beams through the body. It uses two X-ray beams with different energy levels. Fat, bone mineral, and lean tissue absorb energy from the X-ray differently, providing information on body composition.

Getting scanned is painless and takes less than 10 minutes. Here, former Gopher defensive back Cedric Thompson, who went on to play in the NFL and was one of the early users of Dexalytics, is shown being scanned.
Greg Helgeson

With each scan generating 13 pages of data, the team was sitting on a veritable mountain of information. “They didn’t really understand how to use or maximize the use of it,” he says.

Tyler Bosch was a doctoral candidate working in Dengel’s lab on childhood obesity research at the time. A former college soccer player, he had directed a performance training center in Chicago before returning to the U to earn his Ph.D. 

Dengel also had just received CEHD’s Marty and Jack Rossman Award for creativity and productivity. The two-year donor-funded award came with $8,000 to support research and travel. “That really kicked off our Dexalytics project,” he says, adding that the money helped pay for travel and equipment.

Bosch began digging into the data. “The team gave us free rein to think about how we might best use it,” he says. “The unique thing we learned about DXA is that it gives you these regional measurements—what’s in your arms, your legs, your trunk, what are the differences between your right and left sides.” Understanding how the body’s mass is distributed is critical to understanding how an athlete moves. 

He looked at the requirements for various positions and noticed that those playing across from each other (for example, wide receivers and corners, tight ends and linebackers, and running backs and linebackers) need similar body types. “Truly understanding what your body is will be critical to identifying what your body can do,” he says.

Bosch began developing algorithms for what the ideal player in a particular position looks like. Those algorithms can predict whether a player will be successful in that position, how likely he is to make an NFL team, and what it will take to get him looking like the ideal if he switches to a different position. He was able to predict with 80 percent accuracy, for example, which wide receivers would make the team.

After finishing his doctorate in 2014, Bosch did two years of post-doctoral research in endocrinology at the U’s Medical School. He was studying how exercise affects fat metabolism while analyzing DXA data and building algorithms for other sports in his spare time. “We didn’t have the funding to keep it going,” Dengel says of Dexalytics.


In 2015, CEHD created Educational Technology Innovations (ETI) to turn discoveries made in the college into products that had applications outside academia. “The idea was to think creatively about how CEHD could potentially make money,” says long-time CEHD supporter Jennifer Marrone, ’82 B.S., who has served as an advisor to ETI with her husband, David Short, ’88 B.S.

ETI founder and director Ryan Warren was looking for a potential kick-off project and learned about the work Dengel and Bosch were doing. “We knew there was something there that had value,” Warren says.

Although ETI could develop software that would make Bosch’s algorithms accessible to any sports team, they didn’t have the expertise to help coaches and athletes use the information to improve performance. 

Warren introduced Bosch to Marrone and Short, both medical device industry veterans. They saw potential. “What he was doing was amazing,” Short says. “He was able to pull all that data together and make sense of it. Up to that point, no one had done that.”

Wanting to see more U of M-developed products become viable in the marketplace, they established the Jennifer Marrone and David Short Entrepreneurial Fund at the U in 2016 to support ETI’s work. That funding allowed ETI to hire Bosch in July of that year.

When asked what would have happened to the project without Marrone and Short’s gift, Bosch turns introspective. “It probably would have been put on the back burner and not come to fruition,” he says. “Being able to do this full-time and accelerate the growth of it was an amazing gift.”


As ETI’s lead scientist for Dexalytics, Bosch is now scanning athletes from Gopher football, women’s volleyball, men’s and women’s hockey, basketball, track and field, and rowing, and using that information to help them improve performance. 

Athletic build

Tyler Bosch’s work with Dexalytics led the University of Minnesota to the Consortium for College Athlete Research, a group of five colleges and universities that pool their  DXA data for research purposes. “We’re trying to get normative DXA data out there because DXA is starting to become more widely used in a college setting,” says Bosch, ’07, M.A., ’14, Ph.D. 

At last year’s American College of Sports Medicine meeting, Bosch presented 10 abstracts on norms for sports such as basketball, track and field, baseball, softball, and equestrian based on this data. He’s also working on a study comparing leg composition of athletes who have had ACL injuries with that of athletes who have not sustained such injuries. 

Sara Wiley, strength and conditioning coach for the Gopher women’s volleyball team, has been working with Bosch for the last three years. She says the Dexalytics information has helped her adjust players’ training. “If an athlete has more mass on their upper extremity than their lower, it may not be optimal for their position. So when we train, we spend more time focusing on getting more mass on the lower extremity,” she says. 

The twice-yearly scans also tell whether such efforts are producing changes. “It’s been very educational for us,” Wiley says.

The information also helps when talking to athletes about weight and body composition. For example, one athlete’s scan showed that her summer weight gain was actually an additional 7 pounds of lean muscle tissue. “That’s huge,” Wiley says. “We want them to understand that it’s not about weight or body fat percentage. It’s about performance and creating a more durable, explosive athlete.”

Last February, Massachusetts-based Hologic, Inc. signed an agreement with the U to market Dexalytics to professional and collegiate teams across North America. This month, it will make its debut at the NFL Scouting Combine, where NFL teams evaluate college players who are likely to be top draft picks. “That will be great exposure,” Warren says. 

Although Dexalytics is tailored to athletes, Bosch says they’re looking for ways to adapt it to the consumer market. “Body composition can be a much better way of looking at health,” he says. “Too often, we get stuck on weight [as an indicator]. If you gain muscle and lose fat, your overall weight may not change but you’re healthier and will feel better.”

Marrone and Short are both excited about Dexalytics’ future. “This technology is like a little gem,” says Marrone, who envisions a number of possible applications in health care. “It’s ahead of its time.”

Kim Kiser is editor of Legacy magazine.