Did you use all 3 in parallel on the same run, or is that three separate runs on the same route? In theory there shouldn't really be any accuracy difference between them. They all using the same values from the phone. There's a possibility that one app has used a data type that produces significant rounding errors, but this strikes me as highly unlikely. The only slight caveat being the recording interval might make a difference if you're running somewhere with plenty of tight radiuses such as a running track. If you recorded different distances on separate runs then this will be down to GPS errors in the phone. For a variety of reasons phones tend to report that they have got an accurate fix even when they haven't quite achieved one. Also if you're running in a built up area, expect errors.
I started occasional running/jogging about 7 years ago, progressed to running 6 days a week and then stepped it up a bit this year to more intense (but still under 1 hour), daily runs but still consider myself a beginner.
I've been enjoying regular hill repeats and speed work and running daily for 20-60 mins for about a year and been feeling a lot more healthy (I suffer from depression, severe OCD and BDD). However I just read about 'Runner's face' the other day and I'm quite concerned about it!!
As a BDD sufferer I am very concerned about the undereye bags and lines developing (I'm 27) on my face (to the extent that I avoid having my photo taken altogether, avoid meeting friends and spend a long time trying to conceal my facial features).
According to some sources 'Runner's face' occurs when the retaining ligaments of the face are stretched beyond repair due to constant motion of running, while others suggest it is caused by 'Oxidative Stress', which supposedly occurs during more intense exercise/when exercising at higher heart rates. As I run on hills every day and sprint my heart rate frequently rises to 205 (max: 214) and everyday it rises above 195. Am I damaging my (already fairly ugly) face by running?!
I think this one is going to be difficult to answer, because your BDD will probably influence how you interpret answers given. However I've had a quick read of the research and from a scientific viewpoint it appears to be garbage. Ignore it.
I don't think there's anything really to think about. What might be happening is because you are constantly checking your HR, you are creating some sort of tension in your body which is reducing your running efficiency and raising your HR. Talking is distracting you and causing you to relax. Just use the HR as a general indication of what sort of effort you should be putting in, but don't be a slave to it.
Thanks for a great race today Andy! You even managed to arrange the rain to hold off I was impressed by the amount of marshal's you had out on the course, esp. in the middle of nowhere. Could you pass on my thanks and appreciation.