Apple Watch vs Garmin: Welches Herzfrequenz-Tracking ist Genauer?

Day 39: Apple Watch vs Garmin Heart Rate — Which Is More Accurate?

I wore both at the same time during a walk to find out. Here's what actually happened.

The thing that annoys me about Apple Watch

At rest, Apple Watch only measures your heart rate every 5 minutes. That's it. You glance at your wrist and you're looking at a number that could be 4 minutes and 58 seconds old.

Garmin measures continuously — every second, all day. That's not a minor difference. Continuous HR data is what powers Body Battery, stress tracking, HRV monitoring, and sleep analysis. If your watch only checks in every 5 minutes, entire events — a stress spike, a moment of elevated HR — can be completely missed.

Apple does offer a "high heart rate" notification and measures more frequently if it detects movement, but it's fundamentally reactive. Garmin is proactive.

What happened during the walk

I strapped both watches on and went for a walk — same wrist, same conditions, same route. The comparison was immediately interesting.

Apple Watch took noticeably longer to find a heartbeat. For the first stretch of the walk, it was still searching — showing dashes instead of a number. Strange, given it's worn the same way as always. Once it locked on, the readings settled.

From that point on? They were actually quite close. Both reading within a few BPM of each other through most of the walk — peaks, drops, and steady-state sections all tracked similarly once Apple got going.

The good news for Apple Watch users: during exercise, it does switch to measuring every second. So for actual workouts, the sampling rate gap disappears.

So which is more accurate?

In terms of raw accuracy during exercise: roughly equal. Both use optical PPG sensors on the back of the watch. The technology is the same. Individual fit, skin tone, tattoos, and motion can affect either one.

But accuracy isn't the only thing that matters. Here's the real scorecard:

• Resting HR measurement frequency: Garmin wins. Continuous vs every 5 minutes is not close.
• During exercise: Both measure every second — roughly equal.
• Speed to lock on: Garmin wins. Apple struggled to find a signal at the start of this walk.
• Data usefulness: Garmin wins. Continuous HR feeds Body Battery, stress score, HRV Status, and sleep tracking in ways Apple's intermittent data simply can't match.
• Raw peak accuracy: Roughly equal, with individual variation.

The bottom line

Apple Watch and Garmin are in the same ballpark for accuracy during a workout. But Garmin's continuous measurement means it's collecting data that Apple Watch never even sees — every quiet moment, every stress response, every recovery window between sessions.

Apple wins in some places (the display, the ecosystem, the notifications). Heart rate tracking isn't one of them.