Fit test today

I performed a fit test to try to calculate my maximum heart rate, which came out to 175. This is pretty close to the aged based formula of 170, but makes little sense compared to my ability to have a decent running pace of 165 on Saturday. I did the test on a treadmill incline, so maybe a heart rate of 165 on an incline isn't equivalent to a HR of 165 when running on a flat surface. I certainly was more winded running on the incline. I did some sprints after the test for a little extra kick to the workout.