How often should I re-test HR Threshold? | 80/20 Endurance

How often should I re-test HR Threshold?

Viewing 2 posts - 1 through 2 (of 2 total)
  • Author
  • #7242

    Hi all,

    Just a question after watching some youtube this weekend. I’m currently doing a 100miler training block and it hit me that I haven’t validated my HR lactate threshold since I began (13 weeks). Is this something which is programmed into the training block (that I’ve missed), or, is this something that I should look to achieve in between?


    David Warden


    We build testing into most rest weeks of your plan via the RFF and RT, or with an optional formal 30-minutes re-test. See our document but I Have included the relevant section below for your convenience.

    Using Scheduled RT and RFF Workouts to Verify Zones
    Because your fitness level and lactate threshold can change quickly, it’s important to keep your zones current throughout the training process by retesting your lactate threshold every few weeks. Repeating your chosen field test in every recovery week (recovery weeks fall ever third or fourth week in our 80/20 Run plans) is the theoretical ideal. As a practical matter, however, this is onerous for many athletes.

    Fortunately, your 80/20 training plan includes frequent RT (Running Tempo) and RFF (Running Fast Finish) workouts that may serve as zone testing sessions, as these workouts prescribe uninterrupted segments of Zone 3 work. Most of these sessions feature Zone 3 effort that are less than 30 minutes in duration. Advanced athletes can replace these with the full 30- or alternative 20-minute time trials described above. Another option is to use the “backing in” method of verifying threshold pace or power. Because LTHR changes less than TP and rFTP over the course of a training plan, you can retest either of these variables in the context of RT workouts featuring Zone 3 efforts as short as 10 minutes by adjusting your effort until your heart rate levels off at your previously determined LTHR and observing the pace or wattage that corresponds to it.

    Note that RT and RFF sessions occur less frequently in the L2 and L3 plans because 1) the high volume of these plans makes frequent high-intensity/high-duration testing risky, 2) we assume advanced athletes have a longer running history and are already confident in their lactate threshold, and 3) advanced athletes tend to experience smaller changes in lactate threshold than do beginner athletes. But if you ever feel you’re “outgrowing” your zones, feel free to insert one of the easier testing options into your next recovery week if it does not already contain an RT session.

Viewing 2 posts - 1 through 2 (of 2 total)
  • You must be logged in to reply to this topic.