If you train on a Garmin and track everything else in Google Health, the last few months had a specific, maddening flaw. Your run would sync from Garmin Connect and show up in the app perfectly. Your Cardio Load would not move at all. The workout happened, it arrived on time, and the metric behaved as though you had spent the afternoon on the sofa.
Google Health 5.09, which started rolling out on September 25, fixes that. The fix comes with an important limit that the release notes do not spell out.
What Actually Changed
The release note is one paragraph, under the heading "Cardio Load for Workouts Started in Other Apps":
"Since launch, Google Health has allowed you to connect your favorite apps and devices to the Google Health experience. Now, the workouts you track in other apps and devices and sync to Google Health can count toward your Cardio Load, as long as the other app or device has tracked your heart rate data during that workout. This means workouts you track on other wearables like a Garmin or Apple Watch and sync to Google Health will earn Cardio Load."
One condition matters more than all the rest: the imported workout has to carry heart rate data. Google uses heart rate to decide how much load a session is assigned, so a workout that syncs without it still will not count.
For Garmin and Apple Watch owners that is rarely a problem, because both record heart rate throughout exercise by default. It does mean the data has to survive the trip.
The route in is Health Connect on Android and Apple Health on iPhone. Garmin Connect does not talk to Google Health directly, and Google is running its own health monitoring programme alongside this.
Google Is Not Importing Garmin's Numbers
This is the part worth understanding before you compare screens and wonder why two apps disagree.
Google is not adopting Garmin's Training Load score, and it is not adopting Apple's training metrics either. It is taking the workout data it receives, mostly heart rate plus steps, distance, floors and calories, and running it through its own Cardio Load calculation.
So the number that appears in Google Health is Google's opinion, produced from Google's inputs. Two athletes who run the same 10K can end up with different Cardio Load in Google Health than in Garmin Connect, and both numbers are "correct" within their own system.
That also means Garmin's Training Readiness, recovery metrics and deeper training analysis do not become Google Health metrics just because the workout synced. Your Body Battery stays in Garmin's app.
The Help Page Still Says the Opposite
There is a live contradiction in Google's own documentation, and it is worth knowing about because it is exactly the kind of thing that makes people distrust a health app.
The Google Health Help Center page on connecting third-party devices states: "we currently use first party data only to calculate your sleep score and Cardio Load."
That was accurate until 5.09. It is not accurate now, and Google has not updated it. The rollout began September 25, so the page is simply lagging behind the release.
The distinction still matters in one direction, though: Google genuinely does not use third-party data for your sleep score. Third-party Cardio Load is new and real. Third-party sleep scoring is still first-party only.
What Garmin Will Not Share
The Cardio Load fix does not change the underlying data limits, and those limits are the real constraint on how useful Google Health can be for a Garmin athlete.
Google's own documentation lists what it does not receive from Garmin devices:
- Heart rate variability
- Breathing rate
- Blood oxygen (SpO2)
- Skin temperature
- VO2 max
- Energy burned by the minute or by the hour
- Exercise session maps and routes
- Detailed session data such as lap splits
- Health alerts including ECG and irregular rhythm
Garmin's side of that fence is deliberate. According to Garmin's published sharing documentation, the Garmin Connect app will not share proprietary metrics with Health Connect at all, including Body Battery, training load, aerobic and anaerobic training effect, intensity minutes, running tolerance, endurance score and HRV status.
There is also an asymmetry most people never notice: Garmin will deliver data to Health Connect but will not accept any health data from it. The flow is one-way, out of Garmin, never in.
Apple Watch shares slightly more than Garmin does, including routes, VO2 max and some overnight vitals. For Cardio Load specifically, none of that extra data matters, because heart rate is all Google needs.
What You Actually Get, and What You Lose
The practical result is a reasonable daily picture and a thin training picture.
Your Cardio Load in Google Health now reflects every workout you do, whichever watch recorded it, which is what people asked for. What it will not do is reconcile with the training metrics you make decisions with. If Garmin suggests a rest day and Google Health shows a comfortable target, those two apps are answering different questions with different data, and neither is wrong.
One reviewer who ran a 5K with a Fitbit Air alongside a Garmin found the basic heart rate and distance figures close between the two, with the Garmin providing considerably more depth after the session ended. That is the honest summary of what integration across these platforms looks like today.
The Rest of 5.09
The Cardio Load change shares the release with smaller housekeeping:
- Custom food creation now lets you toggle serving units and meal time more easily, with a fixed bug on iOS where deleted items could still appear in your food list
- Activity logging on the Fitness tab now offers more options through a single "Log activity" button
- Both changes ship on Android and iOS, so this is not a Pixel-only update
Bottom Line
Google Health 5.09 started rolling out on September 25 and finally counts workouts from Garmin and Apple Watch toward Cardio Load, provided the session carries heart rate data through Health Connect or Apple Health.
The important caveats: Google calculates its own Cardio Load from the data it receives rather than importing Garmin's Training Load, Garmin's HRV, VO2 max, Body Battery and lap data still do not cross over, and Samsung-style one-way sharing means Garmin sends data but accepts none. Google's own help page still claims Cardio Load uses first-party data only, which the 5.09 release notes directly contradict.
It is a genuine fix for a genuine annoyance. It is not the start of Garmin and Google comparing training notes.
Sources: Google Health 5.09 release notes and rollout coverage of September 25, 2026, including the Cardio Load for workouts started in other apps entry and the nutrition and activity changes; Google Health Help Center documentation on connecting third-party devices and apps, including the stated first-party-only basis for sleep score and Cardio Load and the list of metrics not shared by Garmin devices; Google Health Help Center documentation on Cardio Load and target load, including the requirement for Google Health app version 4.26 or higher and weekly card loading for Pixel Watch; Garmin Customer Support documentation on sharing Garmin Connect data with Health Connect; published reporting on the Health Connect data points Garmin will and will not share, including Body Battery, training load, training effect, intensity minutes, running tolerance, endurance score and HRV status, and on Garmin delivering data to Health Connect without accepting data back; and independent hands-on comparison of Fitbit Air and Garmin heart rate and distance accuracy across a 5K.