Get ready to run through the gears with this aerobic workout that focuses on constant elevation changes. You will start the first of 2 x 10 minute intervals close to marathon effort and alternate the incline between marathon effort and LT (Lactate Threshold) peak. What is Lactate Threshold? It's the fastest pace you can hold for 45-60 minutes. After your LT peak effort you will drop it back down to marathon effort. After a short rest you do it all again by repeating the pattern to finish the session. This is a great workout to do when you are looking to get in a solid aerobic workout using elevation, but don't want to go deep into the well.