1. The Records Track a Different Person
A step counter reading of 14,000 steps per day belongs to someone with a different commute, a different job and a different joint history. The literature on physical activity is explicit that baseline fitness, age and prior injury shape what a given volume of movement means. A number lifted out of that context carries almost no interpretive weight.
2. Supplements That Promise Everything Distort the Picture
Someone reporting dramatic changes after starting vitamin D, omega-3 or creatine may be describing a change that overlaps with better sleep, less alcohol load or a resolved deficiency. Reviews of supplement research repeatedly note that effects are small or absent in people who were not deficient to begin with. Copying the supplement copies none of the surrounding conditions.
3. One Reading Is Not a Trend
Resting heart rate varies with caffeine timing, hydration, illness and how well the strap was seated. A single low reading posted online says nothing about what a different person's heart rate does across a normal week. Clinicians look for patterns across weeks, not isolated points, before drawing any conclusion.
4. Fasting Glucose Responds to Habits, Not to Comparison
Fasting glucose is shaped by the previous evening's meal, sleep duration and stress load. A number that looks impressive in someone else's chart may reflect a short overnight fast rather than a favourable metabolic state. A systematic review of screening data notes that interpretation depends on fasting length, medication and recent illness — none of which travel with a screenshot.
5. Training Sessions and Recovery Do Not Transfer
Four training sessions per week is a meaningful load for one person and an overload for another. Recovery, sleep latency and morning energy score all shift with age, nutrition and accumulated fatigue. Comparing session counts without comparing recovery is comparing half of a system.
6. Embarrassment Silences the Useful Questions
Much of the harm comes from what comparison discourages. A symptom tracker kept privately over weeks produces better material than a comparison against a stranger's exported data. Bringing a question list to a consultation is awkward for many people, but it is far more informative than a screenshot.
7. The Records Were Collected for a Different Purpose
Consumer devices optimise for engagement, not diagnosis. A 12-week plan written for one person's goals will not map cleanly onto another's. The literature is candid about this gap: wearable-derived metrics correlate with clinical measures in some domains and diverge in others, and the divergences are not always predictable.
Quick takeaway: Someone else's records describe someone else's body, routine and reasons for measuring — they are useful as context, not as a target.
