Today I ran four miles in 40.5 minutes, 2% incline on treadmill. It was a good run, but I was hot and sweaty (or felt more so than usual). The treadmill, of course, provides no wind resistance. I was a little tired and don't know if it was due to true tiredness or from my little injury yesterday. I realized today that I need to start increasing the incline. I have been doing a 2% incline for a while now.