Watch Face Changing Colour During Run

I've noticed that my display has been changing to black during my run activities (this is primarily what I use my 5x for) and then back to normal. At first I thought it was related to my heart rate but I can't determine any particular point at which it switches?
Can anyone enlighten me as I can't seem to find any answers by searching?

Thanks.

0 timo231072 over 7 years ago

Linant

maybe you have avtivated autoclimb?

0 Starskins over 7 years ago

maybe you have avtivated autoclimb?

It's either that or your ghost (you against your own time)is beating your time.

0 tdlundin over 7 years ago

I've always wished that the background would change to the color of your HR zone so that you could glance down and see real quick, but that is too complicated for Garmin to program in.

0 jonah2940 over 7 years ago

maybe you have avtivated autoclimb?

Thank you, I think it is autoclimb as I turned of the virtual partner and it is still doing it.