Apple Health app miles walked are inconsistant
Hello.
I have an iPhone 5s; I walk the same route every morning. Sometimes the Apple Health app records it as 3.35 miles; sometimes it records it as 2.65 miles. Does anyone know what is causing this inconsistency? I don't expect the Health app to match other apps like Map my Walk, but I do expect the Health App to consistently match itself. I'm confused.
Thank you.
Elizenda
iPhone 5s, iOS 8.3