Google Health Fitbit updates bring smarter activity detection

Health Guardian is Google’s name for a set of background health tools that look for slow changes over weeks, not moment-to-moment readings. On the Fitbit Air and the new Fitbit Edge, it adds two reports: blood pressure trends and insulin resistance trends.

Neither one measures the real thing. There is no cuff and no needle. Instead, Google’s models look at signals the tracker already collects, such as heart rate, heart rate variability, activity and sleep, and estimate whether your numbers are drifting in the wrong direction. Insulin resistance, in plain terms, is when your body stops responding well to insulin, so sugar stays in your blood longer. It is often an early step toward pre-diabetes.

Google is careful about what this is not. The company says the insulin feature is not meant for medical purposes and is not a pre-screener for diabetes. The blood pressure paper behind the feature has not been peer reviewed, and its study left out people with heart disease, the very group most likely to want the data. Treat a result as a nudge to talk to a doctor, not as a diagnosis.

Health Guardian reached Pixel Watch 3, 4 and 5 owners in late September at no cost. Fitbit Air and Fitbit Edge owners only get it with a Google Health Premium subscription, which costs $9.99 a month or about $100 a year. Premium also unlocks the AI Health Coach, which can explain a change in your trends, adjust your fitness plan and give you extra context to bring to a doctor.

That price gap matters. The Fitbit Air sells for about $100 and the Edge for about $180, so a year of Premium can cost as much as the tracker itself. Older Fitbit models are not included at all. It is also unclear what happens if you own both a Pixel Watch and a Fitbit; Google has not said whether the free access carries over.

The features arrived on Fitbit in version 5.11 of the Google Health app on both Android and iPhone. Once you have it:

1. Open the Health tab in the Google Health app.
2. Tap Heart to set up blood pressure trends.
3. Tap Metabolic to set up insulin resistance trends.

Reports land on the first day of each month, based on the month before. If you set things up now, your first Fitbit report arrives on Nov. 1. The wear rules are different for each report. Blood pressure needs five days in a row of daytime wear in the previous month, and you don’t have to sleep with the band on. Insulin resistance needs seven days and seven nights of wear, which don’t have to be consecutive.

Early users have reported mixed reactions online, including people with normal checkups who got worrying results. That is the trade-off with trend estimates: they can raise flags that a doctor’s test later clears.

The second big change is automatic activity detection. Your Fitbit or Pixel Watch used to recognize 10 types of exercise. Google says it now recognizes more than 100, including strength training, swimming, team sports and racket sports.

The system also uses more context than before. It looks at your usual routines, your history, the edits you make by hand and, if you allow it, your location. Google says this makes detections nearly twice as accurate and cuts missed workouts by more than half. When you confirm or fix a logged activity, the feature learns from it.

Here is how logging works by default. Any session that lasts at least 15 minutes with a sustained raised heart rate gets saved automatically, and a summary shows up in the phone app, usually within half an hour. You can change that minimum. The upgrade covers Fitbit Air, Fitbit Edge and Pixel Watch 3, 4 and 5.

Google Health is also pulling in more outside data so you can see it in one place:

• Abbott Lingo: people in the US will be able to connect Abbott’s over-the-counter continuous glucose monitor, so real glucose readings sit next to meals, workouts and sleep.
• MyFitnessPal: Premium MyFitnessPal users can now share detailed, food-by-food logs, while free users keep sharing daily meal totals.
• Function Health: US users can import clinical lab results starting later this fall.
• Flo Health: a multi-year deal will let you sync Flo with Google Health early next year for insights tied to your cycle phase and life stage.

Google also added Metal Mesh bands for the Fitbit Air in Champagne Gold or Polished Silver for $69.99. A bundle with a Champagne Gold band and an Obsidian Fitbit Air costs $149.99 and is sold only at Target and the Google Store.

If you own a Pixel Watch 3, 4 or 5, update the app and switch on Health Guardian; it costs nothing. If you own a Fitbit Air or Edge, the activity detection upgrade is free and worth having, but the health trends only make sense if you were already thinking about Premium. And whichever device you use, a monthly ‘not high’ result is not a substitute for a real blood pressure check, especially if heart disease runs in your family.