Today I used the Workout app to gather data on my 2.5 mile outdoor exercise walk. As I am walking I can view the current time of the walk, distance, average heartbeat, etc, including a "minutes per mile" calculation. I usually walk at a rate of a hair over 15 minutes per mile. As I look at this number as I walk, sometimes it reads 15 min/mi, sometimes over 17min/mi. And it changes values as I walk pretty much at the same speed. This isn't right, and it got me to thinking. So I took the AW (with my iPhone 6 on my belt) to my driveway when I got home and did some tests. I measured a 76 foot distance, and took several readings as I walked this distance, using Outside Walk on the Workout app. I must have walked this 76 foot track about 20 times and took a reading of distance at the end of each trial. Low and behold readings varied all over the lot from 22 feet to 44 feet to 78 feet to 122 feet! Huh? (Note that I wasn't trying to record my speed or how long it took me to walk the 76 feet. I was just interested in how long the AW thought the 76 feet were. Answer: anywhere from 22 feet to 122 feet. And the way the readings were displayed was weird: it would stay at zero of a long time than jump to 12 feet then stay at 12 and jump to 50, and then jump to 90... Yes, the iPhone was connected to the AW the whole time. My conclusion: the AW/iPhone combination can't measure distance worth a darn. The AW was touted as a great device for fitness, and it can't measure distance for outside walking and jogging and running? Bah! Of course 76 feet is a pretty short distance compared to the much longer distances that people will walk/jog/run when they are working out. But I did not like the way that the distance stayed at one number and then jumped to a much bigger number. If I had hit pause or stop anywhere while the distance wasn't changing I would get wrong calculations. I expected the distance to change regularly every few seconds, and readings were communicated from the iPhone' GPS to the AW. Go figure. I wonder how often GPS readings are taken by the iPhone. If it is every 5 seconds people running on a circular track are going to get bogus numbers if the iPhone or AW computes distances by subtracting GPS readings. Any thoughts?