- select the 'random' program - most treadmills should have one of these
- once the belt starts, bump the incline down until the maximum grade during the program is 5% or less. On some treadmills that are equipped to go to negative inclines (ie downhill) this will create a 'rolling hills' type of profile. The downhill intervals are typically maxed out at about a -2% grade, but this will effectively give you a sort of rest period. If your treadmill doens't include negative grades, you may want to lower the maximum incline to 3 or 4%. This will create more 'flat' sections (ie RI) but these won't be as easy as running downhill.
- Choose a starting pace that would put you in Z3/3+ but that you could confidently (and relatively easily) keep for the entire run, were it to be flat and get up to this pace within the first 2-3 minutes. This is your 'base' pace and you won't go slower than this the entire time
- every 5 minutes, based on the upcoming hills and valleys (which will be different every time), your level of percieved exertion, and the time remaining, decide whether or not you think you can speed up. The catch is, when you speed up, you commit to not slowing down (ie after 15 minutes you think 'hey, i'm pretty comfortable at this pace - i think i could push it a bit' you need to make your best attempt to maintain your new speed, or faster, for the duration of the run).
By having to assess your present state every five minutes with the ultimate goal of only ever increasing (or sustaining) your speed for the entire workout, you will eventually learn, perhaps after some failed attempts in which you had to slow down, how to better make judgements about your abilities based on feedback from your body. When the ultimate goal of a race is to finish the entire distance as quickly as possible this can be important. typically if you run so hard that you can't sustain the effort, the end result is a time slower than what would have been possible had you chosen a different pace. The second benefit is practice in maintaining a pace over slight gradients. since the maximum gradient in the workout as given is 5% or less it's not really simulating a significant hill (5% means 5 feet of elevation gain over 100 feet of distance) but even a few percent grade will be noticable, and effort will be required to keep from slowing down. In a race setting such a hill is often unnoticed visually and an untrained athlete might respond to the increased level of exertion required by slowing down, sometimes carrying the slower pace up and over the hill onto flatter ground. By developing confidence in 'charging' these slight inclines and learning to recognize how they change your percieved exertion you'll race (or just run) more efficiently when the time comes.