Wearables Update Understanding of Sleep
Wearable technology is changing the way researchers understand sleep and its relationship with other health behaviors. A collaboration between Monash University and Brigham and Women’s Hospital is leveraging mobile health technologies to bridge basic sleep physiology, clinical trials, and public health policy.
Sleep data collection has traditionally been a fragmented snapshot of a person's typical experience. However, the increased adoption of wearable technology is changing this dynamic, allowing researchers to analyze multiple dimensions of sleep health, along with wake activities, over extended periods in users' natural environments.
Wearables have become a key focus of a renewed collaborative partnership between Monash University and Brigham and Women’s Hospital. This international alliance aims to leverage mobile health technologies to bridge basic sleep physiology, clinical trials, and public health policy.
Synergy with Sleep
The advantage of wearables is that they can capture in great detail all behaviors, including posture, sleep parameters, and physical activity parameters. This allows researchers to measure the small day-to-day changes that questionnaires invariably miss, making it possible to study how sleep interacts with other lifestyle behaviors-and how those interactions influence long-term health.
Monash-Brigham researchers are discovering that sleep may have a greater impact on health when considered alongside other daily behaviors rather than in isolation. Epidemiological studies consistently show that relatively small improvements across sleep, physical activity, and diet can work together to produce meaningful health benefits.
| Improvement | Sleep | Physical Activity | Diet |
|---|---|---|---|
| 5-10 minutes of sleep per night | - | - | - |
| 2-4 minutes of moderate-to-vigorous physical activity per day | - | - | - |
| Half a cup of fresh vegetables daily | - | - | - |
The combined effect appears to be greater than the sum of its parts. Achieving a similar reduction in cardiovascular risk through any one behavior alone would require substantially larger changes-for example, roughly 30 additional minutes of sleep per night. “There seems to be a synergy,” says Emmanuel Stamatakis, PhD, director of Brain Park at Monash University’s Turner Institute for Brain and Mental Health.
Sleep Regularity Index
Wearables have also helped elevate another dimension of sleep health that until recently received far less attention than duration: sleep regularity. The Sleep Regularity Index (SRI) measures how consistently a person is asleep or awake at the same time on consecutive days.
| Study | Participants | Hours of Data |
|---|---|---|
| UK Biobank | Nearly 61,000 | Over 10 million |
Continuous wearable monitoring made the metric possible. In a collaborative, cross-institutional study using more than 10 million hours of accelerometer data from nearly 61,000 UK Biobank participants, researchers showed that sleep regularity was a stronger predictor of all-cause mortality than sleep duration alone.
Research Versus Consumer Wearables
Despite the proliferation of wearable devices, a divide remains between research-grade and consumer-grade technology. Research-grade devices are valued for their transparency and validated algorithms. However, they often lack the multi-sensor capabilities found in modern consumer smartwatches and rings.
Consumer-grade devices are more technologically advanced and user-friendly, leading to higher long-term usage. However, the barrier to their use in rigorous academic research is the proprietary nature of their algorithms. “By not making the data processing algorithms transparent, it is very hard to use them [in scientific research] because the consumer-grade wearables become black boxes,” Stamatakis says.
Global Public Health Implications
The data generated by wearables is expected to influence the next generation of public health recommendations. Current guidelines have historically focused on exercise and sedentary behavior. Future updates are likely to incorporate sleep into a more holistic 24-hour approach to health.
The collaboration between Monash University and Brigham and Women’s Hospital is helping to shape the future of sleep research and public health policy. By leveraging mobile health technologies, researchers can bridge basic sleep physiology, clinical trials, and public health policy, ultimately leading to a better understanding of sleep and its relationship with other health behaviors.
