Wearable Fitness Data Pilot Study in Psychiatry

From Psychiatry to the Pavement: What a Wearable Pilot Study Tells Us About Fitness Data

Digital remote monitoring technologies, including smartphones and wearables, offer promising avenues for early detection of psychosis relapse. However, selecting devices that are acceptable to participants and produce high-quality data remains challenging.

Samsung, Apple, and Fitbit: Real-World Acceptability Differs

In a pilot study from the CONNECT cohort, researchers at the University of Manchester and King’s College London gave 105 participants with psychosis a choice of three wearables. The Samsung Galaxy Watch was selected most often (43.8%), followed by the Apple Watch (25.7%), and Fitbit Charge (21.9%). This strong preference for mainstream smartwatches over simpler fitness bands was clear. The team, including authors Sam Bladon and Til Wykes, noted that user demographics differed across device groups, suggesting personal choice is not random but linked to lifestyle or tech familiarity.

After three months, a Wearable Device Satisfaction Questionnaire revealed high overall acceptability. The Fitbit Charge 5, however, stood out with the highest proportion of positive responses. This finding is instructive for endurance athletes: the device perceived as most comfortable and satisfactory for 24/7 wear might not be the most technologically advanced or popular option. Comfort is a primary driver of consistent wear, which directly determines the quality of longitudinal data needed to track metabolic adaptations.

Heart Rate Data is the Most Fragile Metric

The study’s most relevant finding for Zone 2 training involves data quality. The team assessed data completeness—the number of valid days for step count, heart rate, and sleep. While step data was largely robust across all devices, heart rate data emerged as the fragile link. Collecting a continuous, valid heart rate signal for effective heart rate-based training proved challenging.

Researchers measured the proportion of participants who provided at least three days of heart rate data per week over 20 weeks. Performance declined over time. This “data decay” highlights a critical point for athletes: maintaining the technical setup, battery life, and proper skin contact for optical heart rate monitors requires active user engagement. The study reported that “a considerable amount of troubleshooting was required” to support data collection, a reality often glossed over in marketing.

Choosing a Device for Metabolic Fitness: Fitbit Retained for Research Rigor

The CONNECT study had predefined criteria for selecting a device. If none were clearly superior and the Fitbit was non-inferior, it would be retained for the main study. Based on the combined evidence—high participant satisfaction and acceptable, though not flawless, data quality—the researchers chose to keep using Fitbit devices.

This decision was made for a large-scale, longitudinal research project where consistency and participant burden are primary concerns. It does not declare Fitbit the outright “best” device. Instead, it emphasizes that for scientific monitoring, reliability and user compliance can outweigh having the latest sensor array. For the endurance athlete, this translates to prioritizing a device you will wear consistently and whose data you trust over one with features you rarely use. Reliable data is the foundation for adjusting training load and assessing whether your Zone 2 training for metabolic health is producing the intended physiological effects.

Applying Psychiatric Research to Endurance Training

The core challenge in the CONNECT study—obtaining high-fidelity, long-term physiological data from free-living individuals—is identical to the challenge faced by an athlete monitoring their fitness. This research provides a transparent, evidence-based framework for evaluating a wearable.

First, consider data completeness over granularity. A perfect heart rate reading during one workout is less valuable than good-enough data collected 90% of the time over six months, which reveals trends in resting heart rate and exercise response. Second, understand that all wearables require maintenance. Regular charging, firmware updates, and ensuring a snug fit are necessary for quality data. Third, recognize that acceptability drives consistency. The best device is the one you don’t think about wearing.

While this study did not directly validate the accuracy of these devices for athletic heart rate zones, it rigorously tested their practicality in the real world. That practicality determines whether you have any data to analyze at all.

Frequently Asked Questions

Does this study mean Fitbit is the most accurate tracker?

No. This study assessed acceptability and data completeness, not raw sensor accuracy against a medical-grade gold standard. It found the Fitbit Charge 5 was satisfactory to users and provided data reliable enough for longitudinal research, leading to its selection for a larger study.

Why is heart rate data harder for wearables to collect consistently?

Optical heart rate sensors require consistent skin contact, minimal motion artifact, and adequate peripheral blood flow. Factors like a loose band, tattooed skin, cold temperatures, or high-intensity exercise can interrupt the signal, leading to gaps in data that step counting does not experience.

Should I choose a smartwatch or a fitness band for training?

The study showed a strong participant preference for smartwatches (Samsung/Apple), but higher satisfaction with the fitness band (Fitbit). Your choice should balance desired features with comfort for all-day wear, as consistency is the most important factor for tracking trends in metabolic fitness.

Sources:
https://pubmed.ncbi.nlm.nih.gov/42413039/
https://pubmed.ncbi.nlm.nih.gov/42412242/
https://pubmed.ncbi.nlm.nih.gov/42308476/