Inaccurate Heart Rate when on treadmill

When I'm on the treadmill my Garmin Vivoactive 4s shows my heart rate as WAY LOW. I'm out of breath and sweat is dripping and it says my HR is 95 while the machines always say 150+. The Garmin seems to accurately measure my HR when I jog outside (same intensitywould measure HR at 150+). Help! It's making me CRAZY!

  • I found the same issue when tracking activities. The only way I could get a better reading was to get a chest strap. I got the Garmin HRM Dual, but supposedly any Ant+ chest strap would work. I still find it reads a little low sometimes unless I am very sweaty. 

  • Same on my Vivoactive 4S.  I've taken to using the Strength app for Treadmill activity as that gives me a more realistic heart rate.

  • I have the same issue with my Vivoactive 4.  I've also had the same issue with previous fitbits in the past.  Not sure if any wrist based HR monitoring works for me when the pulse gets above 120-ish.  Seems accurate when idle, or walking.  For me it only loses the plot when my pulse is above 120.  When doing an activity, similar to other posters, I'll use a chest strap which works well.  My VA4 will connect to the chest strap, and use that over the wrist based readings.