WearablesJanuary 20269 min readBy FitnessToWear Editorial

Chest Strap vs Watch: Heart Rate Monitor Accuracy Tested

We ran the same 20 workouts with a Polar H10 and 5 smartwatches. The accuracy gap is bigger than you think.

Polar H10 heart rate chest strap sensor

Wrist-based heart rate has improved, but once intensity changes quickly, chest straps still produce cleaner data and more trustworthy interval readouts.

Why wrist sensors still struggle

Sweat, movement, skin tone, tattoo coverage, and abrupt changes in pace still challenge wrist-based sensors. That matters most in HIIT, rowing, and hill work.

Who should buy a chest strap

If you train by heart-rate zone, follow a coach, or want clean interval data, a chest strap pays for itself quickly. Casual users can stay with a watch.

Bottom Line

Use a watch for convenience. Use a chest strap when training zones and interval precision actually matter.