Merging, splitting and repairing Strava and Garmin activities

Job by job

“Not documented” means Garmin’s support pages don’t describe it, which isn’t the same as Garmin saying no.

First, get the original file

Every fix outside Strava’s own menus starts here. On strava.com, open the activity, click the three dots and choose Export Original. You get the file in whatever format it was uploaded in, often FIT. There’s also Export GPX, and a TCX version if you add /export_tcx to the activity’s address; both need GPS data. Strava only offers exports on the website, not in the app.

On Garmin Connect’s website, the gear icon on an activity has Export File (the original, usually FIT), Export to TCX, Export to GPX and Export Splits to CSV. The download comes zipped, so unzip it before you do anything else.

For everything at once, Strava has Download your account under Settings, My Account, and emails you a link, which may take a few hours. Garmin’s version lives in Account Data Management, Export Your Data. Garmin says the link typically arrives within 48 hours but can take up to 30 days, and the activity files are in the DI_CONNECT folder.

Crop the start or the end

This one is built in on both. Strava’s Crop is in the three-dot menu on the website and in the app (Crop Activity there), with sliders for the part to keep and, in the app, arrow buttons that move the ends one second at a time. It only works on activities with GPS data, so some indoor ones are out. There’s no undo. If you crop too much, the only way back is to delete the activity and upload the original file again, so export the original before you crop.

Garmin Connect calls it Trim Activity, under Edit Activity in the app and on the web, and you trim the start or end by time or by distance. Unlike Strava, Garmin keeps a Restore Original button. The catches are on Garmin’s own FAQ: the map route of a GPS activity doesn’t change, GPX and TCX uploads can’t be trimmed, several activity types (strength training, yoga and swimming among them) aren’t supported, and some numbers, like Training Effect, Training Load and VO2 Max, stay as they were. Garmin’s FAQ also says a trim doesn’t update Strava, so crop it there as well.

In the file, GOTOES can trim a file’s start and end times in its merger, and FIT File Editor can cut the start or the end off a FIT file.

Cut out the middle (you forgot to stop your watch)

Neither platform does this in one step. Crop only removes data from the beginning or end, and for a bad stretch in the middle Strava’s crop article says to split the activity first and then crop. Split lives on the website only and works on GPS runs and rides. You pick two or three pieces, drag the orange lines to where you want the breaks, and each piece becomes its own activity with the original name. Kudos and comments stay on the first piece. Split can’t be undone either, so export the original first. You end up with two activities where there was one.

To get one clean activity with the middle gone, you need the file. FIT File Editor can cut a section out of a FIT file and recalculates laps and totals around the gap. GOTOES trims each file’s start and end times in its merger, for example to skip the part of a second recording that overlaps the first.

Split one activity into two

Strava’s Split tool, above, is the only general-purpose split on either platform. Other activity types have to be switched to a run or ride first and switched back afterwards, as Strava’s split article suggests. Garmin Connect can divide a leg of a multisport activity into several, or delete one and fold it into the previous leg, with Restore Original to undo it. Of the tools here, GOTOES added a Split GPS Files tool in September 2026: you place cuts on the map or chart, name the pieces, and download each as GPX or TCX (FIT for donors), with laps and totals recalculated for each. Its merger can also export one sport from a multisport file. FIT File Editor doesn’t split.

Merge two activities into one

Strava can’t. Its merge article points to two outside tools by name: FitFileTools for FIT files and GOTOES for TCX, FIT or GPX, noting that GOTOES also handles overlapping files. Garmin’s support pages don’t cover merging.

“Merge” covers two different jobs. One is back to back: the watch died and you started a second recording. The other is overlapping: a bike computer recorded the route and a watch recorded your heart rate over the same hour, and you want both in one activity.

GOTOES does both. Its merger takes FIT, GPX, TCX or CSV files (or a ZIP of them), and for overlapping files you choose which stream to keep from each: heart rate, power, position, cadence, elevation, distance and temperature. Free use allows 20 files per merge, 14MB each and 19MB in total. Exporting the result as FIT, importing straight from your Strava account and the Garmin-to-Strava tool are for donors ($10 or more for a year, or Patreon from $3 a month), along with double the file size limits. Free users download GPX or TCX. GOTOES says a GPX can carry the power, cadence, heart rate and temperature Strava shows; TCX has no temperature.

Combine.Run is for the back-to-back case on runs and rides. You connect Strava, it finds the pieces, and it fills the gap between them by interpolating GPS points; you can click the map to add waypoints so the filled-in line follows the road you took. It uploads the merged activity to Strava for you, with a note in the description that part of the track is interpolated, and can hide the originals rather than delete them. It asks for read and write access to your activities. You can also skip the login and merge GPX files in the browser. It’s free and may show ads.

FIT File Editor merges FIT files back to back in the browser, with distance carrying across the join. It refuses files that overlap in time, so it’s no help for the two-device case.

Fix bad GPS, heart rate or power

Once a device has recorded bad GPS data, the only thing Strava can do is ignore parts of it. You can’t move or delete points on Strava. What you can do, on the website, is Correct Distance, which recalculates distance while throwing out outlier GPS points, and Correct Elevation, which only shows up for files from a barometric altimeter (or, rarely, when an earlier automatic correction failed). Both are in the three-dot menu and both revert if you click them again. Garmin’s support pages don’t cover editing GPS or sensor data.

In the file, GOTOES has an Edit Points window that flags suspicious points (a bad timestamp, a coordinate out of range, a single point that jumps away and back) and lets you delete them, including all the flagged ones at once. Its help also describes deleting or dragging heart rate spikes there, and filters that discard heart rate or power readings above a ceiling. FIT File Editor lets you drag, smooth or delete GPS points and edit a selected range of heart rate, power, speed, cadence or elevation.

Repair a corrupt FIT file

If Strava says “partially corrupted file, could be truncated”, it has already kept what it could read, and it says the rest can’t be recovered. For a Garmin file where the date jumps into the future, the fix Strava points to is FitFileTools’ time fixer. Garmin Connect’s upload error page lists the usual causes (GPS trouble, the device losing power mid-recording, a transfer cut off) and says some third-party repair tools may recover a corrupted file, but that Garmin doesn’t provide or support them.

GOTOES says its merger reads corrupted FIT files that some other tools can’t open, and you can clean up the offending points in Edit Points before downloading. FIT File Viewer recovers data from a partially corrupted FIT and offers a fixed copy to download for Strava or Garmin Connect, working in the browser. FIT File Editor keeps every complete record it can decode and tells you when the rest was unreadable. Whatever the watch never wrote stays missing.

Bulk edit

Strava’s bulk editing covers two things: who can see your past activities, and whether your heart rate shows. That’s in Settings, Privacy Controls, Edit Past Activities, on the website or in the app. There’s no way to change gear or activity type in bulk, and no bulk delete either; Strava suggests the My Activities page on the website, where you edit each one without leaving the list. Garmin’s support pages don’t cover bulk editing.

Strautomator runs rules over activities you’ve already recorded, not only new ones. Set a rule (for example, a gear or commute flag based on conditions you pick) and ask it to batch-process a date range. The free plan reaches back 30 days and PRO ($9.99 a year or $39.99 once) about ten years (3,650 days). Its FAQ says a batch can take up to 24 hours because of Strava’s rate limits, can’t be reverted, and that it can’t delete activities or set them to Only You, because Strava’s API doesn’t allow either. GOTOES has a spreadsheet uploader, but that creates new manual activities; it doesn’t touch the ones you have.

Putting the fixed file back

Strava won’t hold two copies of the same activity, so the order matters.

1. Export the original and keep it somewhere safe, in case the fix goes wrong. Save the photos, and copy the title, description and any private notes, because deleting takes them with it.
2. Fix the file.
3. Delete the activity on Strava: three dots, Delete, confirm. Strava has no bulk delete, so a merge means deleting each piece. (Combine.Run is the exception: it uploads the merge for you and can hide the originals instead.)
4. Upload the fixed file on the website (strava.com/upload/select). Strava takes FIT, TCX and GPX files up to 25MB, up to 25 files at a time with a subscription and 15 without. Strava doesn’t allow two versions of the same activity at once, so if the upload is refused, check that the original is really gone.

Deleting removes the kudos, comments and photos, and none of that moves to the new upload. Strava’s help doesn’t spell out what happens to segment efforts or achievements from the deleted activity.

If you record on Garmin, you don’t need to touch Garmin Connect at all. Upload the fixed file to Strava yourself; activities sync one way, from Garmin to Strava. If you want the fixed copy on Garmin too, you’d delete the original there and import the file, and Garmin says deleting removes any badges or personal records tied to that activity. Garmin also says activities uploaded to Garmin Connect sync on to Strava, so if the fixed file is already on Strava, Strava would likely refuse the second copy, since it doesn’t allow two versions of the same activity. The Garmin Connect and Strava page covers the sync itself.

Exporting without editing

Sauce for Strava, the browser extension, adds an export of any activity to TCX, GPX or FIT, according to its project page. RunGap on iPhone can export activities in TCX or GPX to other apps, Dropbox or email, with some export features behind its paid Swag Bag. Neither edits the file.

Common questions

Sources

• Strava Help: crop tool, split tool, merge or combine activities, bulk editing, bulk-editing privacy, bulk delete
• Strava Help: exporting your data, getting activities to Strava, bulk upload, deleting an activity, restoring a deleted activity
• Strava Help: bad GPS data, how distance is calculated, elevation FAQs, corrupted FIT files, corrupted time data
• Garmin Support: trimming an activity, editing a multisport activity, editing an activity, exporting data, empty TCX or GPX exports, deleting data, upload errors, linking Garmin Connect with Strava, and Strava’s exporting files from Garmin Connect
• GOTOES: merger (limits), its help text (merging, trimming, donor features, formats, Edit Points), changelog, donations and spreadsheet uploader
• Combine.Run support; FIT File Editor on cropping, merging, fixing data and files that won’t upload; FIT File Viewer; FitFileTools
• Strautomator plans and FAQ; Sauce for Strava on GitHub; RunGap help on Strava and Garmin Connect