Started running outdoors again. Really stopped running late last year. I've noticed that my heart rate is great when it is cold outside-ie remains in the 150s range and creeps up into the 160s range at the end of my run. I remember that even in when I was in better shape, if you increase the outside temp, my HR jumps into the 160s range as an average HR for the duration of the run. Ran about 5-6 miles Friday and will try again today.