ATC 324: Recovery Intervals – How Much Rest Do You Need? And More on The Science and Art of Rest Sets and Avoiding Common Mistakes

February 12, 2021


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On this episode:

Matt asks:

Recovery intervals – what difference do they make in performance gains for endurance athletes?
Hi! I’d love to hear more on the science of recovery intervals and why they matter so much (some say they matter even more than the work interval). What does “full recovery” mean? What difference to my training/fitness does it make if I take full recovery vs. partial recovery? How do I know what kind of recovery interval I need for certain workouts, for example 400s or 800s on the track vs. hills vs. mile repeats, tempo, and longer stuff. Do/should recovery intervals change with the season? What’s the benefit to “incomplete” recovery intervals (i.e. either maintaining a certain intensity or a very short recovery interval)?
I’m looking to apply this to both marathon training and probably triathlon in the future (once racing starts to happen safely again).

What the coaches say:

  • What does it mean to have a full recovery?
    • Depends on the intensity and goal of the workout, and what you want to get out of it.
    • Intensity is based on energy systems.
      • If you want full recovery, you have to fully recover each energy system that you use.
      • Each energy system takes a certain amount of time to recover. For example, the PCR (phosphocreatine system) takes about 2 minutes. But to fully recover lactate, it can take up to 15 minutes.
    • Too much (or too little) rest isn’t good. Too much rest can shut down the Krebs cycle and the whole cycle will have to start over again once you start your next interval. Every individual’s Krebs cycle is different depending on fitness level.
    • The Step Test is a basic fitness test that measures heart rate and recovery; typically, the quicker the heart rate drops down, the more fit you are.
    • Full recovery will be very subjective to where you’re at as an individual.
    • Typically, the number one mistake athletes make is that they don’t take long enough rest intervals.
    • The study mentioned: The effects of recovery duration on psychological and perceptual responses of trained runners during four self-paced HIIT sessions.
      • Conclusion: “Longer recovery durations may facilitate a higher external training load (faster running), whilst maintaining a similar internal training load (physiological stimulus), and may therefore allow for greater training adaptations.”
  • When does it make sense to do incomplete/partial recovery?
    • The only time partial recovery is not a good idea is when you’re working on speed. Partial recovery is okay, but as long as you recognize that you’re not working on speed.
    • The question: Is the quality of form, breakdown, and injury risk increasing when there isn’t proper recovery in between intervals?
    • There is an optimal level of intensity for lactate clearance (about 50%-60%). For example, if your doing an interval at a 6-minute pace, jogging at a 9-minute pace for the rest interval would be better than standing still.
  • Tawnee recommends the Jack Daniels’ method if you’re training for a marathon; he clearly states what recovery should look like for each type of workout.
  • The Maffetone method would recommend listening to your body.
  • Tabatas have a great basis in science, but is it worth the risk? And can you do something better that is safer? Lucho would reserve tabatas for the elite of the elite.
  • What do you want to get out of the workout during hill intervals will determine your recovery interval length.
  • For tempos, RPE is the best. Lucho will prescribe his athletes a total amount of volume he wants them to run; the athletes can break it up however they need to get that volume.
  • A 1-minute rest (even up to 2-3 minutes) will not affect your workout outcome.
  • Jack Daniels’ VDOT Chart allows you to factor in seasons.

Comments (2)

  • Sam says:

    Hello Tawny and Lucho,
    I listened to ATC 324 last night and Lucho was about to say something about running 8x 400m in the context of how many or how much was too much, but then shifted gears before finishing his thought on this. I’m curious to know if he was about to say…4x 800 is plenty, or 4x 800 is too many, or the number itself isn’t that critical, but…
    Thank you for all you do,

    • admin says:

      Hi Sam,

      From Lucho: “I was going to use 8 X 400 as an example of a session with possibly too many intervals. Usually people use 400’s specifically on the track at a fairly high intensity because the interval is so short, 1 mile down to 800m race pace which is HARD. If that is your goal, then 8 is most likely too many and you risk cooking yourself. As we mentioned in the podcast, it will depend entirely on what you want to get out of the workout though. If you dial back the speed and shorten the recoveries then it’s a good workout, not much different than my 10 X 1:00 on 1:00 session which can be run at ~5k pace, if you’re fit then possibly 3k race pace no problem. And I know Chrissy Wellington used to run 20 X 400 on 1:00, but the pace was more like (IIRC) 10k race pace. So it depends on what the goal is and whether or not the speed is appropriate to the number of intervals.
      I think the point is that you should go into a workout with a specific goal in mind, whether that be pace and/ or volume and once you see signs that you are struggling to meet those goals then you should end the workout. I tell athletes to stop once you feel you are racing to hit the splits.”

      Hope this answers the question!

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