Fitness trackers range from basic step counters to full GPS watches. Here's how to match the feature set to how you actually train.
The three questions that narrow the field
Do you run outdoors? If yes, built-in GPS matters. Without it, you're either carrying your phone or accepting inaccurate pace and distance data.
How long do you want the battery to last? Optical heart rate plus always-on display drains a battery fast. If you want a week between charges, the display needs to sleep, or you need a larger battery.
Do you care about sleep tracking? Sleep data quality varies widely. The best trackers compare well against polysomnography for sleep stages; the worst only detect movement and call it sleep.
The specs that don't matter as much as marketed
HR accuracy claims are often marketing. What matters is consistency at exercise intensity (HR can spike erratically on some sensors). SpO2 is useful for altitude or illness monitoring; for general fitness tracking it's a nice-to-have.
The shortlist
We compared 10 trackers across accuracy, battery life, GPS quality, and daily wearability. The picks above are the ones we'd actually recommend to someone training seriously at home.
A note on fitness apps
The companion app matters as much as the hardware. A good tracker paired with a weak app hides the data you're trying to use. Check what the app surfaces before committing to the device.