I’m still reading this thread (a bit behind), but I’ve seen you state this like it is gospel truth that all TR sweet spot workouts average (roughly) the same kJ burn rate as endurance workouts. I don’t find this to be the case.
Just looking at a handful of recent workouts my average power is anywhere from 30-50 watts higher on a sweet spot workout than on an endurance workout.
Not really addressing any of the other points you or others have been making, my apologies for that, but I don’t think this part of your fundamental assertation is correct
Highly recommend last week’s Empirical Cycling Podcast! The entire +2hr podcast is a long Q&A session between Kolie Moore and Coggan. Give it a listen. It will clear up all of his thinking, including the meaning of the table!
One thing I noted from that session was that he seems to argue for do as much volume/intensity as you can recover from. Less time → more intensity. He also mentioned as an example of endurance vs. threshold in terms of mitochondria, that 5000m runners have far more of it, than marathon runners
The first 2 minutes of that video chapter, ISM never said Fat Max. Not following the detour into Fat Max,
ISM said zone2 work improves mitochondrial function, and markers such as lactate clearance and fat oxidation and more . Those that do different intensities don’t improve as much. Trial and error, going back 20-30 years, lately we’ve even looked at mitochondrial respiration.
With all that experience, ISM’s conclusion is that zone2 is the intensity that seems to improve mitochondrial function the best.
This is from Skiba’s new book Scientific Training for Endurance Athletes and while I’ve heard it before, what really drove home the point of Henneman's size principle - Wikipedia was listening to several Kolie Moore podcasts.
(LT is lower aerobic threshold, not exactly % FTP zone2 but ‘more precisely’ defined by lactate)
(Critical Power is basically FTP, but a smidge higher)
I’m not sure how that isn’t physiological
the point of staying under LT is to maximize training of Type 1 slow oxidative (slow twitch) muscle fibers. Sure, some type IIA fast oxidative glycolytic are firing, but its mostly your slow oxidative fibers. There are studies showing you get faster at LT by training under it, versus mixing training with most under LT and some over. I’m assuming that is one reason the Norwegians are measuring lactate during training.
I can’t recall where ISM draws the zone2 line, perhaps its there, or perhaps he says to teeter tooter +/- around LT. I forgot.
Anyways lets stay with Skiba’s interpretation of the science. He summarizes it here:
(Lactate Threshold is lower aerobic, not exactly % FTP zone2 but ‘more precisely’ defined by lactate)
(Critical Power/Speed, or CP/CS, is basically FTP but a smidge higher)
Again that is Skiba’s interpretation (references in parentheses so you can look up studies), and a point-of-view that should have fairly wide agreement amongst exercise physiologists but of course they might argue the finer points.
Personally I find that a better expected adaptation chart than the Coggan expected adaptation chart, but I haven’t had a chance to listen to the latest Kolie Moore / Coggan part2 podcast.
I’m still not seeing anything special about Z2 based on the first image. Looks like you keep using Type 1 fibers (even a slight uptick) after LT, and just add on type 2A. From that chart, I would assume that as long as you can recover from the effort, going above LT is only beneficial? Since were focusing on time crunched athletes here, I’m also assuming that training time is restricted by life commitments, not recovery time.
Up to you to decide, good info is out there and its your body, your response to training.
Time crunched for me is 6 hours, that’s currently my “can’t drop below this because fitness really starts to slip.” Work/family/allergy stress sometimes rears its ugly head from time to time, restricted my training time or requiring dropping intensity down to z1/z2. I never feel bad about going out and doing really low intensity.
I dunno, buy the book. It is a good book and filled with references. He doesn’t spend much time discussing that, IIRC one study from runners, one from British rowers. I’m not training that way.
I think the issue here is that intensity ramps up the fitness quickly but is a short gain as you plateau or see a decline in performance. It comes at an increased risk of injury. This is ok if you are ramping up for a race and have only 6 weeks. It is not sustainable long term without the aerobic engine that comes from volume.
Here are the two most recent ones (I’m not doing a ton of sweet spot right now due to the time of year - I’d have to dig around to find other examples)
Gibralter -3 (subtracted the warm-up and cooldown)
Ok so you’re not comparing apples to apples? I misunderstood your point I guess. I can update the data once I’m back at my computer if you want, but that workout has a really short warmup and cooldown, maybe four minutes total
My interpretation of what ISM said, not what I do.
Time optimized. Disruption in time.
I’m of the same opinion, and followed your previous posts. FWIW about 3 minutes into my warmup there is a section of road that I sometimes need to give 500+W for about 10-20 seconds, to bring my speed up to 25mph thru a bottleneck in the road (to be nice to the drivers behind me).
On that particular route my zone2 work starts about 15 minutes later. Most of the time my power:HR have settled into the same state as an easy warmup, but occasionally my HR stays elevated for whatever reason. That’s all I have to measure with - life isn’t perfect, and I haven’t bothered to figure out if there is any other cause&effect. Doesn’t seem to impact anything. Practical point of view.
As an aside, I’m having a hard time understanding the focus some have on fat max. From my point of view the primary point of zone2 / endurance training is to increase fatigue resistance of slow oxidative muscle fibers, but it also has some other benefits. Last pic from Skiba’s Scientific Training for Endurance Athletes
I didn’t hear ISM saying anything to the contrary. If you want to optimize time then do steady zone2, its not like doing a hard effort is going to ruin the workouts, its just a speed bump, a minor disruption, that takes away time from doing focused work.
I think it depends on context and it feels a little like you’re moving goalposts
It’s easily possible to get more kj per hour with sweet spot workouts than with endurance workouts. That’s the point I was addressing because you’ve been claiming throughout this thread they were roughly the same
As to weather or not sweet spot is effective or not, that’s clearly a very nuanced discussion and I’d argue there isn’t a single right answer. It depends too much on the person, their goals, their training history, etc
A dogmatic adherence to sweet spot is just as silly as a dogmatic adherence to all Z2
Maybe, if you can do the 70% day after day without any undue fatigue. A couple of the sports scientists on Twitter have said that the increase in mitochondria is also directly related to the number of muscle contractions and that if you are in the right ball park the actual power level doesn’t matter that much, you’ll get more benefit by increasing your cadence in that hour.
Totally agree and my understanding is that in Z2 the lactate produced from the carbs is used for fuel in the mitochondria rather than accumulated in the blood and hence the stress to your body is much reduced.
- life isn’t perfect, and I haven’t bothered to figure out if there is any other cause&effect. Doesn’t seem to impact anything. Practical point of view.
