I ran 18 miles indoor on the treadmill today because there is approximately 4" of fresh snow here.
I ran on a different treadmill than I normally use and I figured out rather quickly that this treadmill was a little off. If my heart rate is over 140 according to my forerunner, I am running a lot faster than 4.5 miles-per-hour.
I learned a lesson today, if your foot pod for your forerunner needs to be synced, sync it. I have known for sometime that my foot pod has been off a little bit.
But I made good use of this workout, I really concentrated on keeping my heart rate in the upper 130's and seeing how long I could run without having to stop. I had to stop running slightly over 13.1 miles not because I was exhausted, but because I was out of Gatorade and needed a drink. From that point on I was doing run/walk, until I got my 18 miles in.