VO₂ Max
What it is. An estimate of your aerobic fitness — how much oxygen your body can use at maximum effort. One of the strongest single predictors of long-term health in the literature. How to read it. It moves slowly, over months of training. Ignore week to week. What it needs. A wearable that estimates it, usually from outdoor walks or runs with heart rate.Heart Rate
What it is. Your most recent heart rate reading, with the day’s high and low beneath. How to read it. A spot reading is mostly curiosity. The useful figure is Resting HR below.Resting Heart Rate
What it is. Your heart rate at complete rest, usually measured overnight. Why it matters. One of the most informative single numbers a wearable produces. It responds to fitness over months, and to illness, alcohol, poor sleep and stress within a day or two. How to read it. Your own baseline is what counts — normal ranges across people are enormous. A rise of several beats over your own normal, sustained for a few days, is the pattern to notice.Glucose
What it is. Your latest glucose reading if you have a CGM, or the day’s average if you log by hand. The trend arrow. A small arrow above the units shows which way your glucose is heading — up, down or level.The arrow only appears when the reading is recent, within about twenty minutes.
An arrow is a claim about now, and an hour-old direction is not one — so
rather than show something stale, it disappears.
Protein, Fat and Carbs
What they are. What you have eaten today, by macronutrient, from what you have logged. These only ever fill from hand-logging. No wearable can see your food. Why bother. Two reasons. It turns Calories Goal from a population estimate into something personal. And how much people log is one of the five questions we are trying to answer.Log honestly rather than completely. A day with one meal recorded and two
forgotten is real data. A day reconstructed from memory to look tidy is not —
see Please do not perform.