Please tell us more about your heart rate sensor and about the device or app you are recording your activities with!

Hi Jan

My message follows on from a problem I pointed out before. In a response from Strava dated 10 June that conversation was stopped.

I have an iPhone and, now, a HRM-Pro Garmin heart monitor. Some time ago there was a change in the way Strava displayed the heart rate data. While exercising I could see a heart rate which looked realistic. Higher rate with increased intensity and lower rate in periods of rest. After saving the activity however, the heart rate data would not show up anymore. Initially this was intermittently with some of the date of one activity being shown and then a straight line connecting those data to data of a later point in time. Eventually no heart rate data would show at all. Believing that it was my heart rate monitor (I used a Polar heart rate monitor), I purchased a new monitor. That did not solve the problem. Now I know that the monitor is working as expected because the Health app picks up data for the Garmin as expected.

One of your team has worked on it and in the thread of the conversation it was mentioned that the problem was known to Strava. This morning while doing a workout, the data appear to be recorded correctly and stored after saving (and I had a happy moment!). This afternoon while walking the monitor showed believable heart rates, but after saving the activity the heart rate in the graph went from 76 to 119bpm in the first few minutes and than stayed at 119 bpm without any change for the rest of the half hour the walk lasted. There were stairs, hills and flat areas in this walk and keeping the heart rate exactly at 119 for 30 minutes is impossible. So now I am back at being rather disappointed with the results so far. Could you please look into this asap and get back to me? Thanks Jos

I don’t work for Strava. If after saving the activity completely different heart rates are shown than those you have seen during the activity you should file a support request so they can have a deeper look.

If the value hadn't changed, it looks like your hrm stopped recording - maybe the electrodes weren't damp enough, battery got weak, etc… Strava can't really display data if there's none to work with (good old GIGO principle).

Anyway, if you want some deeper insight, you might need to contact Support as ​@Jan_Mantau suggested. This community hub is a discussion forum where fellow athletes advise each other, we’re happy to help when possible, but we can't fix things for you.

When you record your activity on your iPhone, is the app always open and visible? Or is your phone in your pocket?

One thought from your comment about points being connected by a straight line is that maybe the Strava app doesn’t have background refresh permissions, so it is losing data when the app isn’t “active.”

1. Go to Settings > Battery and turn off low power mode (if it is on)
2. Open Settings > General > Background App Refresh and make sure the toggle at the top is green (enabled).
3. Go to Settings > Apps and find Strava. Make sure it has background app refresh enabled. Also make sure that Location access is set to “Always”

Thanks for your replies guys. I will contact Support. Yes background app refresh is enabled and has always been.