On days that I am not able to hike a trail, or do a walk on local roads, I train on my treadmill and then do some stair sets on my boathouse.  I typically do 2 to 5 miles then 25 to 100 sets of stairs, depending on the time I have and my energy level that day.  Yesterday (Sunday, February 5, 2016) I did 3 miles on the treadmill (40 minutes) and 35 sets of boathouse stairs (20 minutes, 350′ total ascent).   Since I have started training in earnest, my weight has dropped and my energy levels have increased-  I am encouraged!