Comparison
Garmin vs Apple Watch: same signals, different job
Garmin builds excellent hardware, and Body Battery and its stress score are genuinely good at what they were designed for: telling you how much you have in the tank today. Sam does something else entirely - it records one condition month after month and turns that into a document you can hand to your doctor. Before you read further: Sam runs on iPhone and Apple Watch and does not work with Garmin hardware.
What each one is actually built for
This is not a question of which sensor is better. Both read heart rate and heart rate variability at the wrist, both have limits, and neither replaces a clinical measurement. The difference is what happens to the numbers afterwards.
Garmin: readiness for today
Body Battery, stress score and HRV status compress last night and this morning into a single figure aimed at your next training session. The time frame is a day, sometimes a week. That is the point of it, and it works.
Sam: a record over months
Sam follows six Apple Health signals for the condition you picked, adds your symptom days, sick days and medication, and asks a validated monthly questionnaire. After three months you have a trend line, not a mood reading.
Where Garmin clearly wins
Battery life is not close - days or weeks against roughly a day. Multi-sport tracking, mapping, running and cycling metrics are Garmin's home ground. If sport is why you wear a watch, buy the Garmin.
Where Apple Watch clearly wins
ECG on the wrist, and Apple Health as the place everything lands - your watch, your iPhone, other apps you already use. Sam reads from Apple Health, which is exactly why it needs an Apple Watch.
How Sam turns months of data into something usable
- 1
Pick one Medical Program
Choose the condition you actually live with - migraine, asthma, reflux, high blood pressure, epilepsy, hay fever, gout or panic. Sam then knows which six Apple Health signals to follow and which questionnaire to ask. The free tier includes two Prevention Programs and one Medical Program.
- 2
Log what a watch cannot see
A symptom day, a sick day, a drinking day, the medication you took and when. Thirty seconds a day. This is the half of the picture no sensor on any wrist produces, and it is usually the half your doctor asks about.
- 3
Take the monthly PDF to your appointment
One document: your signals, your logged days, your questionnaire scores over time. Not a verdict, not a diagnosis - the raw record of your months, in a form that fits a fifteen-minute consultation.
Sam is a wellness companion, not a medical device
Sam does not diagnose, does not interpret your values and does not tell you whether a treatment is working. It records what you and your Apple Watch document and presents it clearly. Every medical judgement belongs to your doctor. The same applies to Garmin's stress score and Body Battery: both are wellness figures, not clinical measurements.
Questions people ask before switching
Is Garmin or Apple Watch more accurate for HRV?+
We are not going to give you a winner, because the honest answer depends on the model, the fit and the night. Both measure at the wrist with an optical sensor, and both differ from a chest strap or an ECG under some conditions. The bigger practical difference is sampling: Garmin records HRV continuously through the night; Apple Watch samples it in the background rather than continuously. Neither is a clinical measurement.
Does Sam work with a Garmin watch?+
No. Sam runs on iPhone and reads the signals it needs from Apple Health, recorded by an Apple Watch. Garmin hardware cannot supply that, so if a Garmin is your only watch, Sam is not the right app for you and we would rather tell you here than after the download.
Is Body Battery the same thing as Sam's record?+
No, and they do not compete. Body Battery answers how much energy you have today. Sam answers what your last six months looked like. If you want a single number each morning, Garmin is the better tool. If you want to walk into an appointment with evidence, Sam is.
Which one has better battery life?+
Garmin, by a wide margin. Many models run for days or weeks, an Apple Watch is roughly a day. For Sam this matters because the Apple Watch needs to be worn overnight to record nightly signals, so charging in the evening or while you shower is the routine most people settle into.
Can I use both?+
Yes, and plenty of people do. Wear the Garmin for training and the Apple Watch the rest of the time, including at night, so Sam has a continuous record. The two systems keep separate data, and Sam only reads what Apple Health holds.
Bring your months to the appointment
If you want a training and readiness watch, Garmin is a strong choice and we will not pretend otherwise. If you want a record of your condition that a doctor can actually read, that is what Sam does - on iPhone and Apple Watch.
Free tier with one Medical Program and two Prevention Programs · Wellness companion, not a medical device