Hi ​@Review, compare the heart rate of both runs. The higher it gets the higher is the effort score. (And very hot weather definitely increases the heart rate.)

Thanks - that is helpful. Though the RE was much higher compared to an identical run with similar average heart rate….25 cf 100... but I guess the impact is subtle and hydration levels can have an impact too. The higher RE score feels anomalous but I will live with it!

I am experiencing something similar - for about a week now all of the runs are recording a relative effort of about 3 times what they usually do - same heart rate, same pace - I am using an Apple Watch Ultra 2 - looks like you are too - I wonder if there is a new bug that popped up?

​@Review  There were reports from some users that Strava changed their max heart rate without consent on

. Could you check your settings if you are affected?

Hi, I am experiencing the same for about 6 weeks on my bike rides now. For example, my usual commuter route that takes me about 45 minutes had a max relative effort of about 30 so far. Now it was up to 90! I asked support on this but they said they checked it and referred to probably higher heart rates. But for me, that could never lead to that massive rise. The max heart rate saved in my profile seems to be correct and I do not have any indication, that it was changed. Has anyone got more info an this issue? 

​@msc_ascv In case your activities are visible for everyone, could you post one URL of a new and one of an old activity so we can compare them?

Hi ​@Jan_Mantau , thank you for your message. Here are 2 links for the same route:

Rel effort = 90: https://www.strava.com/activities/15206385034

Rel effort = 30: https://www.strava.com/activities/14680327891

Thanks for your support
Marcel

These are good examples. There is clearly a bug involved because the durations in each heart rate zone are nearly identical in both activities. Strava doesn’t publish their formula for the Relative Effort but from my estimation the RE of 90 seems to be the correct one.  If you take the older activity with the RE of 30, change the activity type to something else, save it, change it back to “Ride” and then look at the RE after some recalculation time (30 second or so), does it swing in the direction of 90 too?

Hi ​@Jan_Mantau, thank you for your post. You are absolutely right. I changed the type of the older actitvity (rel effort = 30) and then set it back - and now the relative effort ist calculated to 82! So it seems clear, that there ist some kind of bug. I will get this to Strava support and see, what they think about it. 

I wonder, if other users face the same issue.
 

I posted a similar question to the Strava support site recently and have not received an answer.  My workouts recently are routinely higher relative efforts than the same workouts several months ago, despite having a lower heart rate in many cases.  nothing has changed in my heart rate maximum or zone settings.  It makes me feel great, like I am making progress and my “Fitness” is at an all time high, but I feel this is artificially elevated for some reason unknown to me.

Here is the latest (and probably final) reply of Strava support:

Hi Marcel,

Thank you for sharing this update and for testing with the activity type. That’s very helpful information. Since the Relative Effort value changed after switching the sport type back and forth, it does look like there could be a bug affecting certain activities.

I’ll go ahead and report this to our engineering team so they can investigate further. Unfortunately, I don’t have a workaround to suggest at the moment beyond the re-saving step you already tried.

The ticket was closed after this….