Workout distance awful!

I think it might be something to do with the algorithm they use, as Strava is pretty accurate on my phone, but the watch (and I only ever run with it with my phone with me) always, always measures shorter than my Garmin.

 

Huge? The difference from 7.02 to 6.85 is only 2.45%. This is hardly Huge. Consumer GPS devices are generally considered accurate if below a 3% error.


I also have a 620 and use both. For me the Garmin 620 is my official run recorder and my Watch is for over all fitness.

Until (or if) Apple switches to GPS mapping and not just accelerometer calibration, distance measurements will always be in flux unless you keep a steady cadence and stride length. It is just the nature of accelerometer measuring.

 

I have my watch calibrated the way apple advised to do and its accuracy is stunning! I did a run without my iPhone on a 2km lap and after 3 laps my watch gave me a distance of 6.08km.

The trick is to do the calibrating (and don't use other GPS Apps during that procedure). My first calibration was awful too because I mapped my runs with Nike running (but I don't know for sure that thats the culprit) . I unpaired the watch and re-paired it. Then did four 6km runs with 6- ,5- ,4:30- , 5-Minutes per km and from this point I had a pretty accurate reading across all my runs even running up and downhill.

Give it a try and do the calibration again.

Don't forget that the GPS signal is not THAT accurate. You can easily be of 10m and that adds to the whole.

 

From what I understand the iPhone GPS on calibrates the watch and it does not use the GPS for accuracy. This is something that needs to change. The difference in the distances the OP saw are not that bad and not the end of the world!

 

I am only doing brisk walks, but after several times carrying the phone it is spot on. I have measured from milepost to milepost, so unless the DOT is wrong, mine is giving accurate measures.

 

7.02-6.85=0.17 of a mile and not ¼ mile. 0.17 to 0.25 is a 38% difference and that is HUGE.

 

Have you got a source hat States that's consumer devices within 3% are accurate. 3% can be quite a large number depending on the distance in question

 

How many times have you calibrated? You just recieved it on Wednesday, correct?

 

While my comment was made without consulting any sources here is a test of 12 GPS devices with a combined average error rate of 2%. If you look at the table you must add 0.6% to the error rates because the tester misidentified the test track a ¼ mile when it is 400M (see last paragraph) .

http://www.singletracks.com/blog/gps/gps-distance-accuracy-test-smartphone-apps-vs-dedicated-gps/

 

How did you calibrate it?

 

Simply run with your iPhone. It will auto calibrate every time you have your iPhone with you.

 

In my experience of having run nearly 7,000 miles with different GPS watches, I find them very accurate. Lots of theorists will quote 2% accuracy, etc., but in practice, they have been more accurate than that for me.

For a runner, a tenth of a mile is a big deal. I run races with friends who have a variety of GPS watches. We usually finish within a few hundredths of a mile of one another after a half marathon. We are all slightly higher than then official distance, but we chalk that up to not having run the shortest measured line. On my daily 5 mile run, three different watches measure within one or two hundredths of a mile difference. So, in real life, I would say that my GPS watch has <<1% error.

My iPhone with Runkeeper is typically one or two tenths of a mile off from my GPS watch. I always chalked that up to either the iPhone or Runkeeper's problems. The iPhone only occasionally matches the watch, so I only trust my watch. My gut is that the AW's accuracy is subject to the accuracy of the phone.

I have only run with my AW twice so far, and both times with the phone. I am not so worried about accuracy yet. I plan to give it about 50 miles with the iphone for lots of calibration before I run without the iPhone to see how it does.

 

Cheers, will have a read.

 

Wow!

n of 1

For everyone touting the accuracy of GPS what latitude do you live at? Do you live in a mountainous region or area of constrained skyscrapers? Surely SURELY you've seen moments where the precision of location has dropped off.

It doesn't take too many of those events to wildly change, say, a linear distance measurement over the course of 5k.

It's incredibly accurate. But it's precision varies.

 

800 feet difference is unacceptable? Are you building an airfield and using the Apple watch for a tape measure?

 

Well newbie, as others have posted, if you haven't done the calibration then what do you expect?

 

Posts from non-runners who may never have seen the accuracy of a Garmin, Timex, or Tom-tom running watch. (Just supporting the OP.)

He probably did. Apple says it only takes 20 minutes to calibrate. The OP probably has 6x the calibration time.

 

It takes 20 minutes each time it calibrates, (even non-runners understand this) more individual times the better. Apple instructions: "And, whenever you use Apple Watch and iPhone to walk or run outside in the Workout app, it will continue to calibrate the accelerometer by learning your unique stride length at different speeds, and get more accurate over time."

 

I've been doing runs three to four times a week since I got my watch (anywhere between 3 and 10 miles), and always running with my iPhone. I record the workouts with the Watch's Workout app and with MapMyRun.

On Saturday I did a run that was supposed to be five miles. I really wanted the Workout app to record 5 miles, so I kept going until it hit 5 miles. MapMyRun, at that point, recorded 5.27 miles. That's over 5% difference and that really is unacceptable, considering both apps are using the same GPS data. I really wish I could see the GPS data the phone is using to calculate distance so I could see where it's smoothing out the curve and losing distance.

This is a common theme with all of my runs. The Workout app always records a shorter distance than MapMyRun.

 

less than a 3% difference. The garmin isn't 100% accurate either (obviously). There'll always be some small difference.

 

why do you assume that the Garmin is 100% accurate over the AW? From what I see on Garmin fitness watch test (on the net) there is a 2-3% error that the garmin has when tracking.

 

My main problem is lots of my runs/walks I do with my dogs. Two of them. That means a leash in one hand. So basically the Apple Watch is completely useless because it doesn't use the GPS from the phone. There is no reason whatsoever the workout app should not use GPS from the phone as its primary method of measurement, and use pace count as secondary.

My last run/walk logged 1.28 miles on MapMyRun, and 1.10 on my Apple Watch. That is a 16% difference and is absolutely horrible on Apple's part. I'm very disappointed with this, and so unfortunately need to use two watches when running, my Apple Watch and my Garvin Forerunner, which has ALWAYS been right on the money for me.