I use a garmin footpod that I calibrated on the track and use this for the great indoors. I've run on several treadmills around my town recently - its shown how variable they are for pace info, with Most of them quicker than my garmin.
I set the workout parameters in Garmin, so that tells me to speed up or slow down, rather than the (un)calibrated treadmill. It works for me, and I can work in the units of measure I choose, and also get the cadence data if I was interested. Its an option if treadmills are your thing
Some gyms
