[Anna]

Anna on May 19, 2020 at 9:38 pm · in reply to: How fast do I run on race day? #41905

Hi Reed,

Thank you for the reply. I think I’ve figured out where my confusion is. I had been thinking that the reason that we don’t want to spend too much time in Z2 (if we don’t have ADS) is that it was metabolically too close to Z3 and thus too close to Z4. We would thus be training too many fast-twitch muscles and glycogen-burning pathways if we train in Z2. I was thinking that we thus need to be training in Z1 to get the proper aerobic benefit.

However, you’re saying that the issue is not that the metabolic processes are a problem in Z2 (especially, presumably, at mid-Z2 as opposed to the top of Z2), it’s everything else that’s a problem and potentially too tiring. I re-read the relevant bit in TftUA and it also says this. Right now, my AeT pace is super slow, around 8:15 min/mi pace, and so I can do lots of mid-Z2 day after day forever without slowing (as in, without accumulating meaningful long-term fatigue). But perhaps I am in Scott’s third phase in the metabolic evolution article, such that my AeT pace point might move (hopefully), and then I will have trouble keeping up with that kind of pace every day without it becoming damaging.

I get that TftNA was written with only elite athletes in mind, but my understanding was that TftUA, which is what I read, had those issues fixed and was more useful for less-than-elite athletes such as myself. TftUA repeats over and over that athletes with a small Z3 should severely limit their Z2 time. Similarly, Andreas’s BIG VERT cookie-cutter training plan (not that there’s anything wrong with that) is presumably not made for elite athletes, and it states to not include more than 30 minutes in Z2 in even very long training runs. These make it feel like a very hard rule to never do much time in Z2 regardless of how slow you run (as long as you’re not aerobically deficient) but I guess the coaches have just never met anyone as slow as I am 🙂

I will henceforth use feel and recovery time as well as heart rate when determining pace on aerobic-building runs (all of them). I like the imagery of banking versus withdrawing fitness to help gauge intensity. Thank you!

[Anna]

Anna on May 17, 2020 at 12:17 pm · in reply to: How fast do I run on race day? #41810

I’ve been following this thread because I am in a very similar situation to the OP – similar HR stats, similar goal race. (For me, I have AeT at 155 and LT at 163; a recent training run had an early, but post-warmup, hour-long uphill section with an average HR at 151 and 3.5% drift (Thanks, Douglas Watson!) – that pace felt sustainable for a couple of hours at that incline; I am targeting a 50k race, my first, with 8000′ gain in 14 weeks.) I have been in search of answers to both of the OP’s questions: what is an appropriate race HR target, and what is an appropriate HR target for long training runs. So I appreciate you engaging on this topic, Scott, but your answer has made me even more confused.

Ah, okay, that explains it. For athletes with a narrow gap (< 10%) between AeT and AnT, Zone 2 is much more fatiguing. So it has to be used much less. That’s where the 30′ recommendation comes from. But if you don’t find Zone 2 fatiguing, then you can do a lot more volume in that range.

The fatigue from Zone 2 continues to be a greater factor as the aerobic system improves. Once athletes get the AnT / AeT gap in the neighbourhood of 5%, high-Zone-2 training is nearly as fatiguing as threshold work (Zone 4). Zone 3, the gap between zones 2 and 4, becomes so narrow, that it’s generally avoided except for very specific goal event training.

I get confused when people use terms like “comfortable” or “fatiguing” to describe runs or paces. All paces are at least somewhat uncomfortable, and all paces are at least somewhat fatiguing. So these types of terms have no meaning to me. (“Sustainable” is slightly better, but must be quantified with a time frame. Sustainable for two minutes? Sustainable for eight hours?) So I am hoping you can help clarify what you meant in the above quote.

Are you saying:

1) That our Zone 3s must not actually be as small as we have calculated them, and we measured them wrong, and we must actually have more than a 10% gap between AeT and LT, and so the only thing left to do is to run by feel? The theory being that we’re obviously working with inaccurate HR information because otherwise we would not be finding our Z2 long training runs not particularly “fatiguing”?

2) That as long as we don’t find our Z2 runs “fatiguing,” whatever that means, that it’s “ok” to run our long training runs in that zone and we are still getting the aerobic benefit from that, despite all the extensive wording in your literature and training plans that athletes with small AeT-LT gaps must spend close to zero time in Z2? That we have magic bodies that can hang out in Z2 even though we don’t have ADS and still reap the aerobic rewards?

3) Other?

I was further confused by this:

Perfect! That sounds like the right intensity then.

So if we don’t feel totally dead after the Z2 workout, then it’s the perfect intensity? So the whole recommendations to not spend much time in Z2 if we don’t have ADS only applies if we feel that Z2 is killing us? I understand that Z2 is close to Z3 is close to Z4, but at some point the “slippery slope” argument falls apart. If it so happens that we can control ourselves in Z2 and actually stay in Z2 and not at/above our AeT, is that “ok” in that we are still getting the aerobic capacity benefit? Or should we still strive to be in Z1 absolutely and at all costs, even if it means granny-moonwalking our way up every slope?

Thanks again! This is a great community and resource!