This is taken from the POL for lower volume cyclists thread & I thought it would be interesting to create a stand alone thread. @GoLongThenGoHome linked a paper that included a reference to this paper comparing polarized vs non-polarized training for cyclists.
In that paper cyclists trained using an 80/0/20 (Z1/Z2/Z3 where Z1 is <1st lactate turn point and Z3 is >2nd lactate turn point) or a 55/45/0 training distribution. So the non-polarized training regimen included NO WORK at or above threshold. The polarized training Z3 work was modeled after the Stepto-Hawley âbest caseâ training from their papersâŠthis workout has been in my custom workouts list for a few years now. Itâs basically 4 minutes at ~110% FTP (85% PPO), 90 seconds rest, 8 timesâŠbut in this paper they just did 6x 4min @ 85% PPO followed by 2min rest. So not exactly the Stepto-Hawley protocol as they imply but very similar.
The interesting thing wrt to Over/Unders, Hunter took monocarboxylase transporter 1 & 4 pre/post intervention. MCT1 transport lactate from the blood across a cell membrane. MCT4 transports lactate from âinside the cellâ to the blood. MCT4 up-regulated dramatically in both groups but THERE WAS NO STATISTICAL DIFFERENCE between polarized and non-polarized training.
If you look at a classic TR Over-Under workout (Emerson) you will see that the purpose of the workout is to âeffectively train your muscles to process the lactic buildup while still going pretty hard.â Working a little above FTP âflood the muscle with metabolic byproductsâ and then working a little below FTP allows those âmetabolic byproductsâ to clear.
Sounds like a good theory but the riders in this study were able to up-regulate Lactate-to-bloodstream transport substantially without ever riding at or above threshold. Very, very interestingâŠand maybe a little humorous that so many riders have slogged through hated over/under workouts that could have been done just as well with a tempo workout.
Itâs not just about that no. Itâs about producing efficient mitochondria within the slow twitch fibres that yes burn fat and help you spare glycogen but also produce lots of MCT transporters so your slow twitch muscles can use the lactate produced by your fast twitch muscle fibres as a fuel.
From FastTalk episode 165
Trevor Connor 18:58
What would you suggest for building that lactate clearance? Is it something that you work on in the base season? Or is this in season training thing? Dr. Inigo San Millan 19:07
So, I think that the main time to do this is in the offseason, at least this is what I do with my athletes. I do that in the offseason, and this is what I call the zone two, but 25 years ago people would laugh at these concepts and now people are talking about zone two. But yeah, I think that this is very important because this is the exercise intensity where you are stimulating those muscle fibers type ones in the mitochondria to both clear lactate as well as to burn fat, and as we discussed, this is something that it doesnât take, you know, couple of weeks or so it takes at least two months. So, this is what the best time you have to build this is in the offseason, once you start the season, you donât have much time to do this, you need, as we discussed, to focus on high-intensity exercise and recovery, but you should at least keep simulating here and there that zone two because you will deteriorate. And this is what I see, and Iâve seen over the years, not just enough in cyclists, but in other athletes, that when they stop completely doing zone two, halfway through the season, or towards the end of the season, you see a decrease in fat burning capacity, as well as in lactate clearance capacity, because all they have done has been racing and recovery, but they havenât been able to do this translated into the world of professional cycling at the highest level, this is one of the reasons why, you know, more and more athletes pace their competition quite a bit, and even take time off in the middle of the competition to rebuild the base, or to keep stimulating to take a break from competition and in recovery, and put together good solid blocks of training where they revisit zone two, that is that capacity for mitochondrial function, and then also high intensity. But thatâs what Iâve seen over the years, both in the real world, as well as in the laboratory looking at fat oxidation and lactate capacity, thatâs what it takes.
Interesting side note is Trevorâs reference here to an athlete with what you might call TR/Zwift Racing/Sufferfest/Group ride smash fest/HIIT type fitness.
What heâs describing is someone with tons of MCT4 expression but little in the way of MCT1 to actually make use of it.
Physiology of High-Intensity Work Trevor Connor 15:08
Iâve talked about this on the show before, but one of the best examples Iâve ever seen of what happens when somebody does a ton of high intensity is there was this masterâs athlete that I started working with, he was all intensity all the time, and when I started working with him, he was like, âOh, let me send you this test result that I did.â It was a bit of an odd test where the examiner just had him ride for an hour at about 240-250 watts, which was below his threshold. So, would have been kind of that between VT1 and VT2 type effort for him, and the entire hour he was maintaining his lactates at like, seven or eight millimoles. Which you just look at and go, how are you sustaining that? And I talked to the guy who gave the test heâs like, âOh, yeah, I see this masterâs somewhat frequently. Itâs because itâs not that theyâre producing tons of lactate, itâs that they havenât developed that system.â So, the muscle fibers are pumping the lactate out into the blood, but there are no slow-twitch fibers really taking it back up. So, it just sits there in the blood and accumulates. Dr. Inigo San Millan 16:23
Yeah, exactly. This is why doing lactate testing is a very good surrogate to know what happens at the mitochondrial level, right? If you have solid mitochondria, and you are able to clear lactate coming from the fast-twitch muscle fibers exported by those transporters that I mentioned earlier, the MCT4, and theyâre imported into these slow-twitch muscle fibers into the mitochondria by another transporter, which is MCT1, and theyâre metabolized there for fuel. So, youâre not only getting rid of that escape microenvironment, but youâll see you use lactate as extra fuel, and lactase is a more potent fuel than carbohydrates
Not based on the TR text description accompanying each workout.
âEmersonâs primary objective is to increase your ability to tolerate and utilize the byproducts that accompany riding above your FTP, all while maintaining a reasonably high power output.â
Which is still true! But if we were to take a survey, âWhat TR workouts are hardest?â I bet over/under workouts would make the list. Probably at least top 5.
So for all those athletes that hate over/under workouts, I HAVE GOOD NEWS: donât do them. You can achieve similar adaptation by doing tempo or sweet spot or even just riding a little above your ventilatory threshold.
How quickly do MCT 1 and 4 changes occur (up or down) in response to training or detraining?
Itâd be interesting to know whether those adaptations would change over time. Nothing there was an increase in LTP, does that mean the same number of transporters are better at their job, or is that completely independent?
Itâs actually about fat oxidation which occurs in the same aerobic zone as lactate recycling. So as far as I can tell part of the training adaptation is pushing that fat oxidation zone to a higher wattage which has a dual effect of allowing lactate recycling at higher wattages.
For me, regardless of deep diving into the science, I agree with @Helvellyn - there is a lot to be said for actually being able to mentally cope with the feeling being over threshold. You need to know what it feels like and you need to have confidence you can survive over threshold in a race situation or when a steep climb comes up etc.
He preaches metabolic flexibility, but in my experience doing middle zone moves the needle of improving lactate metabolism much better than z2.
This is from lactate measurements. Z2 work does not lower my lactate at a specific percentage of threshold power, but moves the whole curve to the right.
Very commendable, then. You are wise beyond your years!
But shame on you for knowing and never saying so during the many over/under conversations weâve had on this forum. So many have suffered needlessly because you held your tongue.
But shouldnât the question be: Do this improve your performance? So you have proven data that you can upregulate MCT 1 & 4. But does it actually do anything to improve performance? Do you take your lab results to the race director and say, look, I have more MCT transporters so I win. Itâs a cool research paper and looks good on paper, but paper doesnât win bike races. Iâm being slightly facetious here, but it would seem that the end goal of winning a race or setting new KOMs or whatever should be the factor when determining what is best.
Hypothetical, but letâs say you just do Z2 and/or tempo and you upregulate MCT. Other person does over/unders and doesnât have the same MCT boost, but they increase their FTP, or increase their repeatability, or increase their 5 and 10 minute power. What training is deemed better then?
Well I think youâre just making another argument that over/unders are a waste of time.
Mostly I just think itâs funny that so many people hate doing over/unders and the whole time they were slogging them out the intended adaptation they were getting was not much better than riding tempo. CâmonâŠthatâs a little bit funny, right?
As to what is really going onâŠIâve always believed that up or down regulation of transporters in any membrane of any critter depends on the relative difference in concentration of the substance being transported on either side of the membrane. If the difference is large there will be material UP regulation.
So if you want MCT4 to up-regulate you need a high concentration of lactate in the sarcoplasm. If you want to up-regulate MCT1 you need a high concentration of lactate in the blood relative to the sarcoplasm. Thatâs why no up-regulation of MCT1 was observed in this experiementâŠsarcoplasm already had a high lactate concentration so transport of lactate from the blood to the muscle cell was unlikely to occur (what about up/down regulation of tissues in the body outside the muscle? Thatâs an interesting though).
So for my money the best way to up-regulate the lactate shuttle is the way that generates the most lactate. I know from futzing around with my own lactate response that the best way is hard start intervals sustained at or around threshold. Next best option would be floats. But this data causes me to question even that.
If they get better results Iâm failing to see how theyâre a waste of time. Iâm saying youâre focusing on the MCT transporters as an indicator of results. And Iâm saying that who cares what happens to MCTs? Results are the results.
Maybe they donât upregulate MCTs. Who cares. Again, I think performance should be the test. If you think that tempo is going to give you better performance, cool. But if over/unders are getting you FTP gains, or better mental fortitude, or the ability to keep a break away off the front, Iâll take that. At the end of the day, I couldnât care less what is happening to whatever transporters or proteins if it isnât making me faster. If itâs proven that an increase in MCTs correlates to better performance then Iâm in. If itâs just showing a higher number for one training modality, does it really even matter?
I think they touched upon it in the podcast a few times, but basically theyâve said that itâs fine and dandy to pick out mechanisms and proteins and study them individually. But one, the human body isnât that simple. Things donât happen in a vacuum, meaning that looking at a single transporter isnât the whole picture. But their big take away for me was that performance should be the ultimate determination. Is it making you faster? Thatâs it.
Not me. I just copied and pasted text from over/under workouts.
The main point is this: the stated primary goal of TR over/under workouts is to âincrease your ability to tolerate and utilize the byproducts that accompany riding above your FTPâ I didnât say that. TR said that.
I just think itâs funny that so many people hate doing over/under workouts but they slog through themâŠbut this data indicate tempo work is pretty much as effective at achieving the intended adaptation.
If you want to know what I specifically think about how to adapt and improve your lactate shuttleâŠfirst of all, Iâm flattered by your interest! & second of all, please review my previous post.
Yea, Iâll give you that. The workout text for over/unders says lactate shuttling is the goal. But it also says âtolerateâŠriding above FTP,â which canât be overlooked and doesnât happen at tempo. And again, who knows if those 2 MCTs are the only factor in lactate shuttling. We canât look at single mechanisms in a vacuum.
The intended adaptation is better utilization of lactate. The data shows that tempo may be as good at upregulating MCTs. Those may not be the same thing. They could be, but looking at a single mechanism or a single pathway may be missing the whole picture. Thatâs all Iâm saying. Performance is what matters.
Thatâs why I said race wins or KOMs or whatever your goal is. If your goal is to have a lot of MCTs, cool. Iâd rather win.
