No distance measured for racket sports - Updating native datafield?

Hello,

I published bunch of apps tracing racket sports like Tennis, Padel, Squash etc.

1. The problem is that when GPS is OFF and activvity is supposed to calculate the distance based on steps the distance is extremally low eg. after 1hr activity the distance is 50-200meters. At the same time it can be checked that 2k steps were made during activity. Was this issue ever addressed by garmin? This issue is being reported to me by a lot of users unfortunately.

2. I'm going to implement distance measurement on my side based on avg step length * step count. Is there a way to store it in fit file in such a way that it will replace the native/default distance of activity?

Top Replies

jim_m_58 6 months ago +1

1) Understand that the watch only knows about what it can detect on your wrist. It may or may not sense anything your feet are doing. A classic example is using a hiking pole or pushing a shopping cart…

All Replies

FlowState 4 months ago in reply to SzymonP

This doesn't help much, but I will say that I get decent distance from Stryd or HRM-PRO when I play indoor basketball. I haven't tried distance from the wrist, but it's possible it would be worse than using a sensor.

Of course basketball is a little different than tennis, and you can't ask all your users to use an external sensor for speed, but it would be interesting to see if a sensor gave better results.

1783229 said:
Looking at my indoor tennis events for the past week, it showed me averaging about 0.1 mph. Huge difference from 1.6 mph for outdoor play.

The documentation for CIQ activity recording does mention that different algorithms may be applied to sensor data depending on the activity type you record (which is probably not news to any of us, but it bears mentioning.) Meaning that any discrepancies between distance recorded between various activity types is probably permanent once the activity is recorded (distance is probably not going to change if you change the activity type after the fact, other than possibly being hidden from the activity.)

I know it's probably not an option to change the activity type for your app, but you could try recording other sports like treadmill running, indoor basketball / SPORT_BASKETBALL, or SPORT_GENERIC, just to see if the reported distance is any better.

Then at least you could have some ammo to tell Garmin that there's an inconsistency / bug here.

Based on this thread, it probably wouldn't help to record a different activity type:

https://forums.garmin.com/outdoor-recreation/outdoor-recreation/f/instinct-2-series/294126/tennis-bad-couting-distance

SzymonP said:
First user who reported me issue with distance measurement in tennis activity based on steps told me that it behaved totally different on his Forerunner 645M

Pretty interesting.

SzymonP said:
from what I understood it they are not able to change activity type after sending it to Strava

I don't think that's true. I use strava and I've always seen this option (although I rarely use it.)

What I have seen is that some Garmin activity types (like basketball) are not supported in strava in which case they're assigned some generic type like "Workout".

https://support.strava.com/hc/en-us/articles/216919397-Change-Activity-Type

You can edit an activity at any time to update the sport type. You may not have had the option to record the correct activity type or recorded the wrong type accidentally. Keep in mind you may see some changes to your activity analysis based on the new sport type, including which segments you're matched to. Athletes are no longer able to change manual activities to virtual ones. Virtual sport activities must be recorded initially as a virtual activity using a supported virtual trainer or treadmill.