You need to set up your accurate stride length when running and when walking . Its in advanced settings I used my fitbit and also a GPS based fitness app to record steps and distance accurately then using a decent distance say 3 miles i counted steps and worked out median distance for stride. Do the same for running and then your fitbit will record very accurately. if You do 10K and take 10000 steps its exactly 1 metre per stride but if you run fast itll probably be fewer steps like 7500 then your stride length will be 133 cms (1.33m). Hope this helps
