About one in five Americans are now wearing technology to learn more about their bodies. They have different reasons for wanting to collect the data from devices like smart watches, Oura rings, or Fitbits.

Many are interested in physical fitness and track the number of steps they take, their respiration or heart rates, or their “sleep score.”

Others are managing chronic conditions, like heart disease or diabetes.

Still others, like 22 year-old Rachel Petersen, use their wearables to do both.

Rachel, a compliance, quality and regulatory specialist with the Minneapolis Heart Institute Foundation (MHIF), ran Grandma’s Marathon in June and will run the Medtronic TC 10-mile  in October. She uses her Apple Watch during races and as a training tool. “It shows your overall running time, heart rate, splits per mile, and distance,” says Rachel. “On another screen it shows your heart rate zones of 1 to 5.”

Keeping track of those zones is helpful when people are training, she notes. Zone 1 is 50 to 60 percent of your maximum heart rate, and zone 5 is 90 to 100 percent. “When you’re training, you don’t want to be in zone 5 constantly. When I go for a longer run, I want to stay in zone 3.”

Along with her Apple Watch, Rachel uses the Strava app, a tracking and social media platform for runners and cyclists, to stay motivated. “Many of my runner friends track each other’s progress, which makes it fun.”

Perhaps less fun, but more important, Rachel tracks her blood sugar through a continuous glucose monitor, or CGM. She was diagnosed with Type 1 diabetes 11 years ago. “My Apple Watch is connected to my CGM, so I can see the reading as I run.” She has to keep her blood sugar high enough to sustain her energy as she trains. “Especially on longer runs, it can be hard to keep my number up. Many runners in general use sports drinks to maintain their electrolytes. I use them to get my blood sugar back up.”

Tracking data for heart health

Dr. Joe Jensen, a third-year cardiology fellow at Hennepin Healthcare and the Minneapolis Heart Institute, has studied many wearable devices, which first came onto the broad consumer market in 2009. He recently presented about wearable devices during an MHIF On the Pulse webinar (a physician speaker series focused on heart-related topics). He discussed a variety of devices that help current and prospective heart patients keep track of “Life’s Essential 8: the key measures for improving and maintaining cardiovascular health, as defined by the American Heart Association.” These eight essentials tell us we protect our hearts when we eat better, are more active, quit tobacco, get healthy sleep, manage weight, control cholesterol, manage blood sugar, and manage blood pressure.

Dr. Jensen has used a number of wearables personally. He spends his nights in a Sleep Number bed that tracks how well he rests. He also uses a Lumen, a small hand-held device users can breathe into to monitor their metabolism. The app tells them whether they’re burning fat or carbohydrates, how to eat, and how best to exercise on any given day.

He sees Life’s Essential 8 as a useful framework – with data about each of the eight measured nearly round the clock – for creating “individual risk predictions.” Dr. Jensen says that, by and large, there remains a huge opportunity for the medical profession to incorporate these devices and the data they collect. While infrastructure to analyze the data is coming, right now people who track information like heart rate, blood pressure and sleep quality can share it with their physicians, who in turn use it to create “individual risk predictions and target those at high risk” for a heart attack. 

“These devices will lead to better, more individualized care for our patients, with truly actionable data,” Jensen says.

On a personal level, Rachel says the technology she uses to track her race training and blood sugar “does help me feel healthier. It provides extra motivation to stay active, maybe get in a couple extra steps here and there.

“It’s helpful for a lot of different things.”