Spike & Trough Fixer – + other FIT stuff

Perhaps once a week, I use Fit File Repair Tool, to fix or convert a workout or fix a route file. Perhaps STRAVA won’t accept a certain GPX file or perhaps I want to convert a TCX file to a FIT file for some bizarre reason. Rarely I may also have a file corruption problem – either way Fit File Repair Tool is usually able to sort out my problem – a First World Problem, admittedly.

In some of my watch ‘tests’ I have either run out of forearm space or just think that one watch is enough per arm and, in those cases, my Garmin 935 goes in my back pocket and I rely on the HRM-TRI to cache one HR track as I run. This usually works OK but sometimes periods of between 30 and 60 seconds are missed out for ‘whatever reason’. This doesn’t cause me a great problem but when it comes to comparing HR tracks it just makes the graph look a bit unsightly. Like this…

It’s fairly obvious where the real HRM-TRI track is but YOUR eye is drawn away from the deviations of the other lines and towards the unsightly troughs.

You can see where this is going.

There’s a new feature in Fit File Repair Tool which Matthias kindly wrote for me (well, for the challenge really) to fix it. You enter the number of seconds of a period to search through and it fixes what troughs finds. Here is a ‘before’ image followed by a 10-second fix and a 30-second fix. The end result is not perfect as there are more artefacts towards the end but it fits my purpose.

Here we go

In Fit File Repair Tool the interface looks like the following image and you can also see some other interesting ‘fix’ and ‘enhancement’ options (there are squillions more elsewhere in the tool)

I think Matthias is working on a SPIKE removal tool which should be MORE useful, if anything. And I’m trying to persuade him to do something ‘really cool’ which I might tell you about sometime.

Finally, I’d never really noticed it before but there is an option that might appeal to those of you who like hills (I don’t, despite them being good for me 😉 ). There is an option to erase the existing laps and then re-insert new laps that start at the bottom of the hill and end at the top…pretty cool. IE each lap shows your uphill or downhill performance as one lap…#Handy. It would work for cyclists as much as runners – for power users it would be good to see how well you are able to do consistent powers on each type of incline.

IIRC you can also smooth power readings, correct elevation, add TBT instructions and more.

It’s free to play with but Eu39 to use in anger.

Links to: fitfilerepairtool.info

Last Updated on 20 January 2026 by the5krunner

the5krunner

tfk is the founder and author of the5krunner, an independent endurance sports technology publication. With 20 years of hands-on testing of GPS watches and wearables, and competing in triathlons at an international age-group level, tfk provides in-depth expert analysis of fitness technology for serious athletes and endurance sport competitors. ID