In a Nature Medicine study led by UHN’s Peter Munk Cardiac Centre, researchers evaluated large-scale smartwatch data to assess its ability to signal worsening heart failure risk. (CNW Group/University Health Network)
By FitBizWeekly Staff
A new study out of Toronto is highlighting how consumer wearable technology could play a larger role in identifying health risks—well beyond fitness tracking.
Researchers from UHN’s Peter Munk Cardiac Centre, in a study published in Nature Medicine, evaluated whether smartwatch data could detect early signs of worsening health in people living with heart failure. The findings suggest that changes in daily fitness levels—captured passively through wearable devices—may provide advance warning of potential medical events.
Notably, the study found that a 10% decline in daily cardiopulmonary fitness was associated with more than a three-fold increase in the risk of unplanned healthcare use, including hospitalization.
“Heart failure often worsens silently between clinic visits. By tapping into information captured through everyday wearable tech, this study shows we can detect significant changes much earlier, and potentially intervene before a health crisis occurs,” says Dr. Heather Ross, Head of Cardiology at UHN’s Peter Munk Cardiac Centre and co-senior author.
The three-month observational study followed 217 participants, using Apple Watch data to track heart rate, activity levels, and oxygen saturation. Researchers applied an AI model to estimate daily cardiopulmonary fitness, with results closely aligning with traditional clinical testing.
“We couldn’t have done this anywhere else. This work reflects UHN’s commitment to translating innovation into clinical tools through a highly interdisciplinary team,” says Chris McIntosh, Senior Scientist at UHN’s Peter Munk Cardiac Centre, and co-senior author of the study.
“By combining clinical insight on day-to-day changes in activity capacity with advanced modelling expertise, we can track activity and physiological signals over time and flag declines that might otherwise be missed between clinic visits.”
For the fitness industry, the implications are worth watching. As wearables become more integrated into everyday activity, their role may extend beyond performance tracking into early health detection and preventative care.
While still in the research phase, the study reflects a broader trend: consumer fitness technology increasingly intersecting with clinical health outcomes—blurring the line between wellness tracking and medical insight.
