DUBLIN: Millions of people now start their day with a number – a “readiness” score, a “body battery” level or a measure of “strain” – delivered by the wearable device on their wrist or finger. But how much trust should we place in these scores?
Composite health scores are increasingly used by digital fitness trackers to offer a single, daily number that reflects how your body is coping with recent demands. Whether it’s marketed as a measure of energy, recovery or resilience, the idea is the same: Combine several internal signals into one clear indicator of how prepared you are to take on the day.
The concept has clear appeal. It simplifies complex physiological data – things like heart rate, sleep and activity – into an actionable recommendation: Push harder, take it easy, rest.
But how solid is the science behind these scores? My colleagues and I recently conducted a systematic review of the most widely used composite health scores in wearable devices to find out.
First, what goes into these scores? Typically, quite a lot – at least on paper.
Most composite health scores pull data from several biometric signals – measurements from your body that indicate how it’s functioning. These include resting heart rate, heart rate variability (the variation in time between heartbeats), sleep quantity and quality, recent physical activity, and sometimes breathing rate, skin temperature and blood oxygen levels.
Source: CNA
