14.5 miles at LTF Treadmill (very different response from ACIST treadmill). HR average was 148, true max was about 157. These HR #'s seem a bit high, especially since I had to slow the pace down to 6.7 mph (just under a 9:00 min/mile pace) AND I had to make the incline Negative 1% in order for it to feel comparable to the other treadmills I use. (I've experienced this before on the same treadmill at LTF -- front row, closest to aisle.) But once I adjusted to keep my HR at least within the prescribed range, I kept it steady for 2 hours, 15 minutes, so I would consider this a high quality Long Aerobic Run despite not running at the prescribed pace of 8:39. In other words, the intensity level (based on HR) was appropriate, as was the duration.