How do I add a workout to Garmin Connect without a watch?

Configure the sport, duration and intensity in FIT Generator, download the generated .fit file and import it into Garmin Connect via Import Data. The file contains per-second heart rate records, calories, Training Effect, TSS and time in zones.

How is maximum heart rate estimated?

Without a measured value, HRmax is estimated from age using the Tanaka formula (208 minus 0.7 times age). For women the Gulati formula (206 minus 0.88 times age) is used, which was validated on over 5000 women. A self-measured value always takes precedence.

Does the generated FIT file work with Amazfit Zepp?

Yes. Zepp reads the per-second heart rate records, so PAI accumulates correctly and Training Effect is displayed. Zepp's own training load score is only calculated for native device recordings, which is a platform limitation.

Is my data uploaded anywhere?

No. The heart rate simulation, all metric calculations and the FIT file encoding run entirely in your browser. Nothing is sent to a server and no account is required.

Logging swimming sessions without a heart rate monitor

Typical effort: 70–85 % of maximum heart rate (DiCarlo 1991). Generate a complete .fit file for a session you could not record.

Why the band comes off

Even water-rated bands struggle in the pool. Optical sensors rely on light reflection through skin contact, and water between sensor and wrist plus the pressure of each stroke pull produces gaps and implausible readings. Many swimmers take the band off rather than deal with corrupt data.

What heart rate to expect

Swimming sits at 70–85 % of maximum heart rate for typical sets. Two effects lower it relative to running at the same perceived effort: the horizontal body position improves venous return, and water immersion itself reduces heart rate by roughly 10 beats per minute compared with land-based exercise at equal intensity.

Effort heart rate	70–85 % of HRmax
Source	DiCarlo 1991
Load pattern	See methodology table

Typical session structure

A 45-minute lane session usually runs 200–400 m easy warm-up, a main set of 6×150 m at moderate pace, a short fast set of 4×50 m and 200 m easy to finish.

How to log it

Open the generator and select Swimming.
Enter your age, resting heart rate and fitness level.
Choose a preset or build the session block by block.
Generate — the .fit file is created immediately.
Import it into Garmin Connect, Strava or Zepp.

Everything runs in your browser. No account, no upload, no data leaves your device.

Other sports