Apple Watch indoor run metrics drastically changed on treadmill

Some users reported similar issues when they started to use the new Apple Watch 12 or Ultra 4.

Apple introduced a new algorithm to estimate steps and distance during a workout in watchOS 27.

The watch should deliver better results again over time after a calibration and multiple workouts.

Calibrate your Apple Watch for improved Workout and Activity accuracy - Apple Support

Don't forget to use the Feedback link to tell Apple Techs directly about this issue, the more users do that, the more likely we will see a fix in an upcoming watchOS update.

Feedback - Apple Watch - Apple

Hi, I have also upgraded to Watch 12. I am experiencing the same issue with indoor running. I have recalibrated the watch on my outdoor walk - and the data is fine. I've had another go on an indoor run today and I gave up as it gave me an average pace of 24 mins when it is normally 13 min.

Today I did two ‘runs’ one after the other. The first was an indoor run that had average pace of 25.5 mins/mile. The second was using outdoor run indoors. This had average pace of 16:30 mins/mile. My usual pace is 13 mins/mile (pre watchOS 27) for an indoor run. Calories are 3.6/mins for indoor run and 4.4 for outdoor run indoors. My pre watchOS 27 was 6.2 cals/min using indoor run. Either all of the data that I used since Apple Watch 2 (about 9 years ago) has been incorrect all this time or there is something drastically wrong with WatchOS 27 and 27.0.1

I had done an outdoor walk on my lunch break yesterday, the treadmill run was the same evening. Maybe it will be better after an outdoor run with it on today?

I seem to remember a similar thing happened on my Watch 10. It was after a software update and it did correct itself.

I even did a backup/restore but nothing has changed.

I think everyone using Treadmill should use Ingo2711

suggestion and send Apple a product feedback.

I shut down both my iPhone and the watch. This didn’t work. Then tried the ‘Other’ setting rather than indoor run or walk. This didn’t work either. I live in hope that when I wake up tomorrow it will all be back to normal 🤞

Similar issue with Ultra 3 on os 27...one lap of the mall on an indoor walk is showing 0.5 mile instead of 0.6 mile. I cleared the calibration data and did an outside walk and that didn't fix anything. Fortunately, 'outdoor walk' actually works in this mall to give me the correct 0.6 distance each time around.

Apple's 'new algorithm' needs to be rolled back.

Yeah so even after an outdoor run this morning, and a treadmill run this evening, the problem still isn’t corrected. As a half marathon/marathon runner trying to track mileage buildup during training this is very concerning. Like no way is it taking me half an hour longer with the same intensity to run a mile indoors

It is pathetic that they launched this software. Does no one at Apple run? I don't understand how you release this. I've run outside with my new watch four times, running between 6:59 mile pace and about 7:30. Today, using the treadmill, I ran 4 miles and it clocked 3.19 miles. Apple, be better than this - please fix it. Also, does anyone here know if the Oura Ring does a better job? At this point, I'm about to give up on Apple.

Good luck, after an outdoor run as well, then an indoor run again, the issue still isn’t fixed. Concerning to me when trying to track buildup of mileage as a long distance runner :/

Same here wearing Series 9 and now it takes 12 minutes to run 1 K.

Normally with my speed I take around 6 minutes.

The new watchOS 27 is wrong.

Still the same for me. Calories burned are less than half that I normally burn during my indoor run. i did report this using the link to the Apple techs

Yes! The distance difference between treadmill and watch expands over the length of the workout. So frustrating to not get accurate data!