Training Plans and CTL | 80/20 Endurance

Training Plans and CTL

Viewing 3 posts - 1 through 3 (of 3 total)
  • Author
  • #7100


    I’ve just completed the HM Level 2 plan plus a few weeks to chain 2 HM’s together. With the ongoing COVID-19 crisis I had last week off and have now purchased the 10K L2 plan.

    I have two questions:

    On training peaks, I noticed that the CTL during the 10k plan was effectively a flat line maintaining around 40-43 CTL and Positive form throughout. My first question is, does this matter or should I be increasing the intensity?

    For context my main aim for the next year is to go quicker at Half Marathon, I just really enjoy this distance. I would definitely have an A race next spring and then I might make the switch up to 26.2 for the Autumn.

    My plan for the rest of the year:

    10k plan until July 6th, Week off
    6 weeks of the maintenance plan,
    10k Plan until 9th November when I do have a race(hopefully), Week off
    Half Marathon plan Until the end of March, 2 weeks off
    Consider going for 26.2??

    Is this the correct way to chain together plans across a year? I like the idea of the 10k plan twice as the time trial is a good judge for HM performance.

    Should I be focussing on the CTL as I switch between distances or will this naturally fluctuate? Running twice a day isn’t an option at present so I am limited to the L2 plan.

    Thanks for any advice here, I really appreciate the plans and the advice I have received so far. The last 19 weeks training for the half were much more enjoyable than last year without 80/20 and the results were much better as well :).

    David Warden


    Regarding your predicted CTL, this is addressed in our document Understanding Your Structured Workout Plan and is particularly applicable to HR-based plans, which you have.

    Q: The predicted CTL, TSS or pace seems really off in TrainingPeaks. Why?

    A: Two reasons:

    1) This is a known problem in TrainingPeaks for HR-based workouts. The auto-calculation for predicted CTL or TSS for HR-based workouts has two main issues. First, the predicted TSS value will only increase in units of 10. If you have one run that should have a TSS of 41 and another run that should have a TSS of 49, TrainingPeaks will calculate both as a predicted TSS of 40. Second, for a given amount of planned workout time, and regardless of the planned intensity, TrainingPeaks uses a minimum value. For example, if there are two runs of 30 minutes, one performed at 75% of LTHR and the other performed at 90% of LTHR, both will have a predicted TSS of 40. Thus, TrainingPeaks systematically miscalculates predicted TSS, and therefore predicted CTL, for HR-based structured workout plans.

    This particular issue is limited to the predicted TSS and predicted CTL for HR-based plans only, and does not impact TSS or CTL for completed workouts, nor Pace or Power-based workouts. TrainingPeaks reports they are looking into the issue.

    2) Even with Pace and Power-based workouts, TrainingPeaks assumes that you will be running in the upper quartile of the zone range when predicting average Pace or Power (and therefore TSS). For example, if your Zone 2 run pace was 7:00 to 9:00 minute per mile, TrainingPeaks will assume that you will run an average of 7:30 per mile for a Zone 2 segment when predicting pace, when in reality you could be running as slow as 8:55 per mile and still be following the workout correctly. The inevitable result of Zone training is that your intensity for the day could fall anywhere within a broad range, therefore, the predicted TSS will almost always be incorrect.

    Therefore, you don’t need to increase your intensity any more than what the plan describes. You’ll soon find that the predicted TSS for a given workout is much lower than your actual TSS. In fact, go ahead and find a common running workout, like an RF6, sometime in the future on your calendar. Then compare that predicted TSS to a completed RF6 you’ve recently done and you’ll see the difference.

    What really matters is not CTL, what really matters is are you getting faster? And you are! I don’t think you should be looking at predicted CTL or TSB at all, only current CTL and TSB will be accurate.

    The way you have chained your events together looks great to me.



    Thanks David.

    I missed that page and perhaps got slightly crossed wires from the portion in the book that talks about running more.

    My initial confusion was the half plan did show a progression vs the 10k only showing a flat line but I think this was due to having no CTL before the half vs 19 weeks worth of data before the 10.

    Certainly, after week 1 my CTL is already higher than what was predicted.

    I appreciate the support.

Viewing 3 posts - 1 through 3 (of 3 total)
  • You must be logged in to reply to this topic.