The Google Fitbit Air's 'one size fit' does not fit all

Fitness trackers are supposed to work best when they sit snugly against your skin. That’s how they properly measure heart rate, track workouts, and avoid wildly inaccurate readings. But Google’s new Fitbit Air is already running into the classic problem with “one size fits all” wearables: they rarely fit everyone equally well.

Enchantress11, a Reddit user, recently shared photos showing how oversized the Fitbit Air looks on smaller wrists. According to the user, the tracker is tight enough to stay in place, but it still looks awkwardly large, and the band can’t wrap any further. The images show noticeable air gaps around the wrist, which is exactly the kind of fit issue you don’t want on a device that relies heavily on skin contact for accurate tracking.

Another commenter chimed in, saying they also have “comically small wrists” and appreciated the post because it gave them a realistic idea of how the tracker might fit in real life. The original poster admitted pre-ordering the Fitbit Air felt like a gamble, though they said it still sort of fits.

The discussion quickly turned into a brainstorming session about alternative ways to wear the tracker. Several users suggested placing it higher on the bicep rather than the wrist, arguing that fitness trackers tend to perform better when there’s more surface area and tissue beneath the sensors. But others pointed out that Fitbit’s sensors may not actually be calibrated for bicep placement, which could create a whole new set of accuracy problems.

That has also sparked calls for Google to release optional band sizes or even a dedicated bicep strap — something fitness enthusiasts have been asking for across wearable brands for years. Google had previously confirmed during a press briefing that it neither offers nor has any active plans to develop a bicep strap for the Fitbit Air.

Some users went even further and suggested wearing the Fitbit Air around the ankle instead. One commenter claimed they already use their tracker that way because it produces more reliable step counts. Considering the Fitbit Air doesn’t even have a display, some people argued there’s little downside to hiding it under a sock if it works better there.

Most of the reactions under the Reddit post weren’t mocking the device, though. Instead, many users simply thanked the original poster for showing what the Fitbit Air actually looks like on smaller wrists, so more people don’t spend money on it.

It’s a good reminder that wearable comfort is deeply personal, and a universal fit usually comes with compromises. Bodies are different, wrist sizes vary widely, and a fitness tracker that fits perfectly on one person can look oversized and function poorly on someone else.