In the time since I published my RunKeeper vs. Nike+ comparison, I’ve had several people ask me if RunKeeper is accurate. The short answer is yes, mostly. The slightly longer answer is not always, and when it’s wrong, it’s really wrong.
I should preface this by saying that, overall, I’m a fan of RunKeeper. I started out with RunKeeper Free and quickly upgraded to RunKeeper Pro because I wanted to support ongoing development of the program. That being said…
My early experience
When I first started using RunKeeper, it seemed to lop off a bit of the distance at each end of my neighborhood laps. This is perhaps understandable, as I run down-and-back, and it’s algorithm was probably (I’m just guessing here) rounding off the turnaround point.
Not long thereafter, they released an update that was supposed to provide better accuracy. While they didn’t specifically what they had changed or why, RunKeeper suddenly started reporting very accurate distances along my preferred route. Score one for the RunKeeper gang!
Periodic freak outs
Since that time, I’ve generally been quite happy with RunKeeper’s accuracy. Every once in awhile, however, it simply freaks out. Take, for example, yesterday’s run…
This was a 5 mile run along a known route. While it took me just under 60 minutes to complete (that much is correct), RunKeeper reported that I had covered 45.86 miles while running at an average pace of 1:18/mile. Amazingly, I only burned 1432 calories during this workout.
In looking at the map, it appears that RunKeeper repeatedly “jumped” to a point about five miles away and back again. I’m guessing that it periodically lost the GPS signal and reverted to finding my position based on the nearest cell tower, but I’m not 100% sure.
As for that lost GPS signal, the sky was clear, and there was nothing overhead. Thus, there shouldn’t have been any problems holding a signal. For what it’s worth, I also had wifi turned off on my phone, as this reportedly improves accuracy.
This exact same thing happened to me a few weeks back while out on my first 10k run. Identical conditions (clear sky, nothing overhead, wifi off) and the map showed a similar pattern. Given that this particular run took place about five states away, I know my local geography isn’t causing the problem.
Who’s to blame?
To be fair, RunKeeper relies on the iPhone GPS, and so this problem could very well be due to hardware limitations. In other words, if the hardware loses the signal, the software may be reduced to trying to locate you through neighboring cell towers.
Regardless, those that are interested in using RunKeeper should be aware that it’s prone to freaking out on an occasional run. If you can live with that, then it’s a handy (and affordable!) tool for tracking your runs. If not, then you might want to look elsewhere.