Did the Zones get revised?

  • Creator
  • #71550

    I am confused about the zones. In TFTNA, I see 5 zones defined, whereas in UA recent videos and writings I see 4 of them.

    In particular, Z1 in the book used to be where the majority of training took place, with Z2 being the narrow (5%) no-man’s-land before entering Z3 and approaching your AnT.

    Now, I see 4 zones, with the majority of training taking place in Z2, which spans a 10% range.

    Has there been a regime change here? Is the difference that the original zones and %s in the book were based on max HR whereas now they are based on actual measurements of AeT and AnT (with Z1/Z2 now being expressed as %s of AeT and Z3/Z4 on whether you have crossed the AnT)?


  • Participant
    Daniel Gerauer on #71552

    There is no academic definition for “the zones”. Anyone might define his/her own.

    However UA works with recovery zone, z1 to z4 and z5 (z5 is not really used I believe).
    All is quite detailed in the books plus there is also a calculator on UA webpage.
    Cannot believe they will change their zones.
    Just check the last video.
    Basically put AeT as upper limit of Z2, go 10% down and set this as upper limit of z1 one and another 10% down set this as lower z1 limit. For the upper limit of z3 take your AnT. But it is perfectly explained in the last group session.

    Have fun!

    Cory from Wisconsin on #71572

    If I recall, the Z2 “no man’s land” listed in the book was a result of working with elite athletes where their Z2 is so fast it can cause too much stress/training load to train there for extended periods. Scott and Steve acknowledged in a podcast and or forum posts the first edition of the book had that Z2 no-go as a result of not fully appreciating its usefulness for training us mere mortals 😉

    All current information has high volumes of Z2 for anyone that has aerobic deficiency syndrome with a span of 5% or greater between AeT and AnT.

    Anonymous on #71588

    Here is a cut and paste from the same (similar?) question on the the main thread that Scott answered. Hope this helps your understanding.

    For well trained endurance athletes, which was what my background as an athlete and coach has been, Z2 IS a dangerous zone to spend too much time in. The reason is this: A well trained endurance athlete will have an aerobic threshold very close to his/her anaerobic or lactate threshold. Often these two important metabolic points will be separated by as little as 6-7% in HR. That is going to be around 10 beats. That gives a very narrow Z3 (Aerobic threshold, recall is at the top of Z2 not as the misprint in the book saying Z1). So when the fit athlete is training near AeT he/she is also training near AnT. AeT running pace will often be within 5% of AnT running pace. For these fit athletes, that’s FAST. Too fast to train a high volume. Even though the metabolic stress is the same for any athlete (fit or not) in this aerobic zone, these speeds impose a very high neuromuscular load that needs more time for recovery. Doing a high volume of Z2 for these folks will lead to overtraining. They need to do most of the aerobic base work in Z1 and then do more high intensity work at Z3 and Z4.

    However, when a person with aerobic deficiency (ADS) runs at AeT (top of Z2) the pace will be quite slow. Often these folks are dismayed how slow they must run to stay in their aerobic zone. For them the neuromuscular loads are quite low at these slow speeds. So, those with ADS can handle all or nearly all of their aerobic base building work right up at their AeT. For them Z2 is NOT a black hole.

    How did this make it into the book? With my rather skewed, high level athlete and coaching experience I was not fully conversant in ADS as it presents in recreational and none endurance athletes. I have learned a lot since that time and now see that in order for those with ADS to see their maximum gains they need to train right near AeT.

    george.peridas on #71704

    Ah, that makes sense now. Many thanks, all!

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