Nerd Lab: FTP, VO2max, and Sprints within LSD

Physiologist Rob Pickels nerds out with Coach Trevor Connor for a deep dive into new scientific research.

Cyclists from above

Exercise physiologist Rob Pickels returns to Fast Talk to out-nerd Coach Trevor Connor as they discuss new scientific research in sport science. Though the findings of these studies may not always directly apply to your weekly training plan, understanding the questions that have been asked by physiology researchers can give you context about what is known and knowable by science as it relates to human performance.

In case you missed our last Nerd Lab episode, check out Fast Talk episode 172: Sprinting, Overtraining Your Cells, Durability: Rob Pickels & Trevor Connor Nerd Out on Recent Research.

FTP20 Test Review

The first review, “What is known about the FTP 20 test related to cycling? A scoping review,” revealed there are only a few studies that have looked at the 20-minute test of FTP. The protocols of the different studies varied a lot, so it is difficult to find significant trends.

Overall, this is a thorough analysis of the 20-minute FTP test and how well it predicts/correlates with other measures. For example, it has decent correlation with MLSS and LT2, but shouldn’t replace them.

Interval Protocols and Time Near VO2max

In the next study, “Time Spent Near VO2max During Different Cycling Self-Paced Interval Training Protocols,” the researchers compared 4-minute and 8-minute self-paced intervals with 4:1 and 2:1 recovery ratios. The findings suggest the 2:1 ratios tended to result in more time near VO2max.

But it raises a question: Is time near VO2max the goal? The assumption is that time at VO2max is better for adaptations. Does this assumption drive bad training practices?

Finally, this study also raises interesting questions about self-paced vs. set intensity intervals.

Inclusion of Sprints in Transition Period

The final study, entitled “The Inclusion of Sprints in Low-Intensity Sessions During the Transition Period of Elite Cyclists Improves Endurance Performance 6 Weeks Into the Subsequent Preparatory Period,” looked at whether having some intensity in the transition period will help a subsequent preparation period. The findings suggest that including sprints improved 20 minute all-out TT, but there is still a question of whether there is a physiological benefit.

The test procedure was huge; there were differences between the groups. All that improved was their ability to ride at a higher percent of VO2max. Is it a simple improvement in an athlete’s ability to suffer?


  1. Rønnestad BR, Askestad A, Hansen J. HIT maintains performance during the transition period and improves next season performance in well-trained cyclists. Eur J Appl Physiol 2014;114:1831–9.
  2. Turnes T, Aguiar RA de, Cruz RS de O, Caputo F. Interval training in the boundaries of severe domain: effects on aerobic parameters. Eur J Appl Physiol 2016;116:161–9.
  3. Taylor M, Almquist N, Rønnestad B, Tjønna AE, Kristoffersen M, Spencer M, et al. The Inclusion of Sprints in Low-Intensity Sessions During the Transition Period of Elite Cyclists Improves Endurance Performance 6 Weeks Into the Subsequent Preparatory Period. Int J Sport Physiol 2020:1–8.
  4. Agnol CD, Turnes T, Lucas RDD. Time Spent Near V˙O2max During Different Cycling Self-Paced Interval Training Protocols. Int J Sport Physiol 2021;16:1347–53.
  5. Mackey J, Horner K. What is known about the FTP 20 test related to cycling? A scoping review. J Sport Sci 2021:1–11.

Photo: Brent Olson on Unsplash

Episode Transcript

Chris Case 00:12
Hey everyone welcome to another episode of Fast Talk, your source for the science of endurance performance. Today we have a special episode. We’re calling it nerd lab. We’ve had Rob Pickels on the program before we had him on not that many months ago and we did this very thing. We sit down with him, mostly Trevor and Rob, take some articles, some journal articles, some research, and pick it apart. The Good, the Bad, the Ugly. We’re gonna do that again and we hope to do this quarterly with Rob, because, Trevor, why did we choose Rob?

Trevor Connor 00:46
Well, what you’re probably not good to see on the episode is you get Rob and I together when we’re off mic and we just make fun of each other in a way that, Chris, probably makes you look friendly.

Chris Case 00:58
I can’t even imagine.

Trevor Connor 00:59
So yeah, we have a lot of fun together. But that being said, I have worked with Rob for a long time. And he has one of the best critical eyes for research I’ve ever seen. He can just take a study or take a presentation that somebody is giving, and just dive right into it and find what works, what doesn’t work, what are the issues, what are the things they should have considered? And he’s not the kind of guy that’s going to hold back his opinion. He’s going to tell you what he thinks, which is exactly what we want.

Chris Case 01:30
Yeah, he has opinions and he likes to share them. So let’s hear from Rob, Trevor, and myself now.

Trevor Connor 01:47
Hey, listeners, we started a bi0weekly series on our website that we’re calling FTW or free this week. Every other week Fast Talk Labs will release one story for you, our listeners to enjoy. We’ve already released cyclocross skills and drills from Coach Grant Holickey, our workshop on the training peaks performance management charts, info on chronic training load, and best features of Strava, training peaks, and Garmin Connect. Free articles and videos are waiting for you at Join today at our free listener members level to enjoy this content.

Chris Case 02:31
Hey everyone welcome to another episode of Fast Talk, I’m your host Chris case. We are joined by Coach Trevor Connor today and the orenary-est physiologist we could find to duel with Trevor. Rob pickles. Welcome again.

Trevor Connor 02:45
The illustrious Mr. Pickles.

Rob Pickels 02:47
Thanks for having me guys. Looking forward to it.

Trevor Connor 02:49
I remember this time.

Chris Case 02:50
You remembered this time, we got that in.

Trevor Connor 02:52
I swore every time we have you on the show. I would refer to you as the illustrious Mr. Pickles.

Rob Pickels 02:56
How about illuminated next time? Can we change it?

Trevor Connor 02:58
Oh, illuminated? Yeah, I kind of like that remind me next.

Rob Pickels 03:02

Chris Case 03:02
how about we just shorten it to the ill? The Ill Rob pickles.

Rob Pickels 03:06
I don’t think I’m ill. And I’m not sure that’s a politically correct term at this time. So we’ll just go illuminated.

Chris Case 03:13
All right, very good, ornery, and illuminated. Rob pickles are you ready to duel with Trevor today?

Rob Pickels 03:18
I sure am.

A Review On FTP

Chris Case 03:20
Great. Let’s jump into our first study. This one is entitled, what is known about the FTP test related to cycling a scoping review. Authors are John Mackey and Katie Horner. And they’re working out of Dublin, and the University College Dublin to be specific. Trevor, what’s the overview of this study that we should start with?

Trevor Connor 03:47
So this is a review and I think it’s a worthwhile review that needed to be done because so many cyclists use this 20-minute test to figure out their FTP. Obviously, this is a concept that was created by Dr. Coggins and Hunter Allen. So they write about it pretty extensively in their book. And the idea here is you do a 20 minute all-out time trial, you multiply it by 95%. And that gives you a pretty good estimate of your FTP, your FTP is basically the power that you can hold for about an hour. And that they say in their book correlates fairly well with maximal lactate steady state, which is a physiological marker of kind of the highest level that your body can somewhat sustain, hence, maximal lactate steady state. But this hasn’t been tested that much. And they even point out in the review, there weren’t that many studies to look at. They only had 15 that met their criteria

Chris Case 04:50

Trevor Connor 04:51
15 studies total.

Chris Case 04:52
That’s pretty few given FTP as a concept has been around for how long 20 years?

Rob Pickels 04:58
offhand I don’t know, but it’s universal among athletes. Right?

Chris Case 05:01
Right, yeah. That’s pretty few.

Trevor Connor 05:05
And you have how many cyclists out there, that are doing this 20-minute test and saying this is an estimate of my threshold, and then they are basing all their training zones off of it. So worthwhile to start doing the research saying, does it actually pan out? Does it actually show what you think of showing?

Chris Case 05:20
Very good. Rob, your reactions to this study when you read it? What are your thoughts here?

Rob Pickels 05:28
Yeah, you know, I always whenever we get a study, I look at the title, I read the abstract. And then I start formulating opinions. Now that might be judging a book by its cover. But it informs me on what are the questions that I have about this, when I don’t have enough information, I have to ask myself, what things do I need to know to truly understand what’s going on here? And in all honesty, the first thing that came to my mind was -and, Trevor, I’m going to let you finish the statement,- the best predictor of performance is

Trevor Connor 05:59

Rob Pickels 06:00
Performance itself, right? And so, you know, hey, for me, I’m already on board with this, because it’s a performance-based test. And the reason that’s important is it’s integrating a lot of things, right? It’s integrating the baseline physiology within a person’s body. It’s integrating mental capacities, it’s integrating the ability to perform, and so that’s why performance is a great predictor of performance. The other side of this, though, is that I oftentimes feel that we try to make too many connections between things. For me, the 20 Minute FTP test is good enough to just be a test on to itself. I personally don’t necessarily take it to FTP, we can talk about that more. But I don’t know that we need to make some of the connections that we’re needing to make. in some regard, I don’t even care whether or not it ties back to MLSS, LT2, VT2, all of these other performances that we’re looking at.

Trevor Connor 06:58
So the counterargument I’m going to give- now I agree, and I have read a few studies on FTP, saying that it is reliable, it’s repeatable. So it can actually be pretty good to see improvements in the athlete’s performance. So it can be very valuable for that,- where I have some concerns, and the authors actually bring this up towards the end of the review, they point out that there is yet any research showing that FTP is based on anything physiological, they compare it to CP. So that’s critical power, critical power does seem to delineate that the high intensity versus the severe intensity zones, which is a physiological point. They actually say that critical power is superior because of that, and they say FTP, there’s nothing physiological about it doesn’t seem to demarcate any particular point. To me, that’s relevant, because as a coach, if I’m trying to get my athletes training zone so that they can target in on a particular energy system, and you base it off of FTP, you’re trying to create physiological zones based off of something that isn’t physiological.

Rob Pickels 08:04
100%, all the viewers if we did the Facebook Live like we were talking about earlier, all the viewers can see that I just pointed at Trevor. And that’s because we are taking something that’s not- well, I don’t want to say not physiological right? but we’re taking a performance test and we’re trying to tie it to the underlying physiological occurrences in the body.- And we know for a fact that if somebody goes in a lab, and we test their lactate threshold, their base zone that derives from that is going to be within a range of that lactate threshold. The zones, were always based on what was happening with a lactate curve, it was never about finding the lactate threshold, and then just applying a formula to that, right? And oftentimes that base zone is going to fall within, I don’t know, 68 to 72, maybe some people as high as 75%, of threshold. So there is an individuality to this that’s really important. And just knowing FTP,- in my opinion, Trevor, and I think that you’re saying this,- I don’t know that that’s enough information for me to actually define zones based on that, but that’s not a bad thing. Because a 20-minute performance test is a great marker of improvement, or, in my case recently lack of improvement in your training.

Trevor Connor 09:25
So if this was video, what you’re also not seeing is how often Rob just points at me shakes his head, and just walks away. And actually, if you look at the original version of Dr. Coggins and Hunter Allen’s book, -which they’ve now improved on in more recent versions,- and you look at early versions of some of the software, everything was based off of FTP, all your training zones were based off percentages of FTP, and we’ve now pretty much said, that’s not sufficient. Everybody’s different. You can’t just say well, two people have the same FTP say, 300 watts. All their zones are going to be the same. I agree with you this 20-minute tests can be really good for just doing that benchmark of how are you improving, what’s going on with your forum. It’s not going to show everything, it’s not going to tell whether you’re going to win in a sprint, whether you’re going to be able to cover attack in a race. But if you’re talking about that time trial or breaking away and be able to put out the effort, going out and doing a 20-minute test periodically is going to give you a good indicator.

How to Properly Tackle The FTP Test

Rob Pickels 10:27
Yeah, Trevor, I think that the specificity that you’re mentioning there, that this performance will be really indicative of your performance in certain situations, a steady-state effort where the workload is not varying too much. So time trials, breakaways, like you’re saying, if there is more of an intermittent effort, maybe in a road race or a crit, or in a mountain bike race. I found it interesting that the performance that they tried to tie this back to repeatedly in this paper was to mountain bike performance, which is probably the place that you would get the least accurate results, because of the non-steady-state nature of that. So again, it’s about that specificity of the individual’s and they definitely bring that up when we compared to different laboratory-based tests. When compared to lactate threshold and maximal lactate steady state, they said, hey, this is similar, on average to lactate threshold,- I believe, they said there was a bias of about three watts, so horseshoes and hand grenades and threshold prediction good enough for me,- but there was such an individual variation. Because remember, we’re looking at this with group averages, and the group average might have had a low bias. But if we look from person to person, then there’s a large variation there. And so the author has said, Hey, we can’t necessarily call this equivalent to a lactate threshold test. Because for individual people, it’s not going to be accurate at all. But when we look at that group as a whole, then the averages are going to be appropriate. We see the same thing with maximal lactate steady state in that as well.

Trevor Connor 12:06
So yeah, exactly. Pretty much what they’re saying is, if you do a 20 minute time trial, to get that estimate of your FTP, you can’t then say, well, that’s my MLSS, or that’s my critical power or my lactate threshold. If you took 20 people and had them all do the FTP test, you might get an average that’s very, very close to the average for their lactate threshold. So as you’re saying, in a group, it’s going to match up, but as an individual, you could be higher, you could be lower, you just can’t say it’s the same.

Rob Pickels 12:41
Yeah. And I think that that’s a point of research that’s really important in general, right? So outside of this study, let’s say, we give a group of cyclists a supplement and performance improves 5%. You know, as readers, oftentimes, we think, Oh, good, everyone’s performance goes up by 5%. And that’s not necessarily the case. 50% of people could have had no improvement, and 50% could have had a 10% gain, we can kind of tease that out a little bit with a standard deviation. That’s why it’s important that we include that. But oftentimes, we ignore that number. And we just look at the big headline 5% improvement. But we need to understand, again, the individuality nature of this, which for me is a recurring theme in this paper, that something is neither good nor bad. It just matters whether or not it’s appropriate to achieve the goals that you’re looking to achieve.

Trevor Connor 13:30
Right. And I can tell you from experience, as a coach, you really see exactly what they’re talking about. I have athletes do this 20-minute test all the time. And you’ll have some that are true time trials, they’ll go out and do it. You’ll see their power is steady, their heart rates pretty steady. And you just look at that and go, Okay, this is a true aerobic effort. I have other athletes that go out and do it power is much less steady, you see this dramatic rise in their heart rate over the 20 minutes. And you know, they’re actually pulling in a lot of anaerobic metabolism. This is not a true representation of their aerobic power. So you can see that a bit in the athletes. But if you just say don’t look at that information and say, This is a representation of my lactate threshold, you could be way off. And they actually bring that up, they point out the fact that if you read Dr. Coggins and hunters book, they have a warm-up protocol that’s pretty severe. It’s actually very similar to the 40 P tests where you do a five minute all-out effort, then I think it was rest, about 10 or 15 minutes, somewhere around there

Rob Pickels 14:37
It was 10 minutes of low intensity followed by five minutes of passive recovery. So 45 minutes total, five of which is an all-out VO2 max effort.

Trevor Connor 14:46
And the idea here is to clear out some of that anaerobic energy so that when you get to this time trial, it’s going to be more aerobic in nature. So they do say in this review that the 95% multiplier only really works if you do that warm-up. If you do just an easy warm-up, because a lot of these studies just did 10 minutes a riding easy, they didn’t have that all-out five-minute effort. They actually say in this review that an 88 to 91% multiplier would be more appropriate.

Rob Pickels 15:16
Yeah. And it is interesting because it shows the human way of thinking. Because the author’s that chose to do the easier warm up- easier in quotes, I guess. -But the authors that chose to do the easier warm-up said that, hey, this is the way that we get the biggest, the best 20-minute power following this. And as people, we always want to see the highest number that we can possibly get, whether or not that’s an accurate representation of what’s happening. We still want to get that highest number that we can. And, I found it really interesting, that they pointed out that Coggan and Allen, that they have that five-minute max. And for me, it matters a lot because I think that I’m an anaerobic athlete,- Trevor, as you were saying.- And I realized real quick that 95% does not appropriately predict what my threshold is, I always, even without reading this study, years ago went to a 92% of what I could do, or for me, oftentimes, when I would do it, I would actually do 95% of a 30-minute effort, instead. Trying to make that a little bit longer, trying to make my anaerobic legs hurt a little bit more and have a more accurate prediction of what’s going on there. And, it was interesting with pacing strategy, because as you were saying, a very steady pacing strategy is probably something that we’re going to see from an aerobic athlete, you know, I know in myself as an anaerobic person, I would probably go out a little too hard, try to try to just hang on toward the end there and watch my power, just drop, and I would just look and have an average power for the interval and just be like, don’t lose another watt, just like everything I can to not let it lose one more watt in my average. But from this, they almost said that familiarization with the test was more important than pacing. And I think that anyone who’s done this test, you know that you have to go out and do it a few times before you understand how to do it, before you understand how to put yourself in that place. Right? Because this is not an easy test to do. And because it’s a performance-based test, then that mental aspect, how tough are you? How long can you hold on? How can you endure the suffering? That really is going to impact your performance during this?

Trevor Connor 17:41
Right. And that goes back to your point of the best predictor of performance is performance, you need to familiarize yourself with this test to be able to perform it well.

Rob Pickels 17:48
I agree. But that does not mean that performance is the best predictor of training zones.

Trevor Connor 17:55
Yes. Which is fair. But you know, I hope everybody listening to this. You been a little surprised. But what we’re saying is the multiplier because everybody thinks 95%. And they’re saying that’s only if you did that hard effort. If you did a easy effort beforehand, multiplying by 90% might be more accurate. And I can hear a whole lot of people right now cringing going, but that’s not the number I want. Because I have seen athletes, do this 20-minute tests and then go well, I wasn’t having a good day. So I’ll multiply by 102%.

Rob Pickels 18:27
Exactly, yeah, my power meter must have been a little off. So I’m just going to boost this a little bit.

Trevor Connor 18:32
And that is where you get in trouble. I have honestly had athletes that cannot complete five-minute intervals at what they say is their ft power, and I’ll have the conversation with going what is FTP? Well, it’s what do you hold for an hour? Did you just complete a five-minute interval at that power? No. Could you complete a five-minute power interval at that power? No. Then it’s not your one-hour power.- But I swear it is-.

Chris Case 18:32
That is cooking the books.

Rob Pickels 19:00
Yeah. You know, for the listeners, as Trevor’s mentioning this description- get your notepads and your pencils ready,- because the warm-up that was described by Coggan and Allen is it’s 45 minutes total. It was 20 minutes at a self-selected low-intensity. Three one-minute intervals of fast pedaling, I believe they said over a cadence of 100 with one-minute recoveries, five minutes of low intensity again, followed by that five-minute max effort and then 10 minutes of low five minutes of passive recovery before you start the test. Which is interesting, the five minutes of passive recovery before you start the test you’re going into this baby cold in some regards. Your heart rates come down, your ventilation has come down. But I was thinking you know maybe this is a time that I’d be slamming a gel and recalibrating my power meter and everything else to get ready for it.

Trevor Connor 19:54
So if you’re using this, basically the review says it’s a decent estimate it’s a reliable test, it can show improvements. I just hope you really heard what we were talking about in terms of doing the proper warm-up making sure you’re using the proper multiplier if you are intending to use this data, in order to determine what your training zones are to help determine your training zones, if you fudge it and start giving yourself a much higher number, you might build a brag about that on the group ride, but you’re going to give yourself really bad training ranges really bad training zones. That’s going to hurt your training.

VO2 Max In Different Cycling Interval

Chris Case 20:34
We could talk at length, more about FTP and the 20 Minute tests and what you’d like to see next in the research literature to tease it out even further. But I think we should move on to the next question here- not the next question, the next study.- This one is entitled time spent near VO2 max during different cycling self-paced interval training protocols. It is a 2021 publication in the International Journal of Sports, physiology, and performance. Trevor, do you want to try pronouncing the names of the authors on this study or shall I?

Trevor Connor 21:14
Oh, you’re gonna do that to me. Let’s trade-off. The first author is Cristiano Dall’ Agnol.

Chris Case 21:24
Dall’ Agnol is how I would probably pronounce it. I don’t know if this is a Brazilian team or Italian.

Trevor Connor 21:31
It is Brazilian

Chris Case 21:32
Okay. Tiago Turnes and Ricardo Dantas De Lucas. Pretty good.

Trevor Connor 21:41
Fantastic. Thank you for giving me that first name.

Chris Case 21:43

Chris Case 21:45
So Rob, why don’t you start this time, we’re kind of the brief overview of what was being looked at, in this study.

Rob Pickels 21:54
Yeah, in this study, it was pretty interesting to me actually, if we go back to the title here, it’s time spent near VO2 max during different self-paced, – and I have that highlighted on my page,- self-paced interval training protocols. So what they did was they had subjects go through a series of different intervals, but they blinded the subjects to how hard they were working, but they let them choose their own workload, which is, in my opinion, really interesting and potentially really painful. So the author’s did four different interval lengths, a four-minute on one minute off, four minutes on two minutes off, so same on duration, but double the recovery. They also did eight minutes on two minutes off. So now we’re working for longer, followed by eight minutes on and four minutes off. So the longer work duration, followed by a longer recovery. And during that they recorded metabolic and ventilation information. And they determined how long subjects were at or above 90% of their VO2 max and tried to sort of quantify the effectiveness of the different work to rest ratios based on that. Now, Trevor, I’m going to move on from here with a question. If you were going to do a four or an eight-minute effort to push your VO2. But what percent of threshold do you think you would choose to do that?

Trevor Connor 23:29
Well, this is the big question of the study. And the big thing that I highlighted was, how relevant is time at VO2 max or near VO2 max? Well, with me, specifically, I’m really old and just getting decrepit and weaker so

Chris Case 23:46
Such a positive outlook on life.

Rob Pickels 23:48
Wow. Coming into the holiday season

Trevor Connor 23:51
Wait till you’re 50.

Chris Case 23:53
I will wait. Yes.

Trevor Connor 23:55
You know, for me, it’s just trying to see that number go down less as opposed to what I can do to improve that number. Yeah, that’s a really good question. Because frankly, if I’m trying to improve somebody’s VO2 max and I am a big believer that if you’re a brand new cyclist, you can prove VO2 max, but it’s one of the first metrics that I think you really peak out very early on. So it’s very hard to really improve it beyond dropping weight.

Rob Pickels 24:23
in an absolute sense, once you’re trained, yeah, we see very little changes in VO2 max at that point.

Trevor Connor 24:29
But if I was going to hit somebody with some work to try to hit that higher-end there. So if trying to get them strong for a four-minute climb in a race or those shorter efforts versus a 30 minute time trial, which is steadier, more about lactate threshold, I’m actually giving them really short intervals. I wouldn’t give them a four-minute or eight-minute intervals. I’m going to give them those 30 seconds or one-minute intervals.

Rob Pickels 24:57
And that’s Trevor, the thing that I have that as an improvement upon this study is that they did not include more of the 30-30 the shorter interval VO2 efforts.

Trevor Connor 25:07
So, they actually reference another study from 2016 that was called interval training in the boundaries of severe domain effects on aerobic parameters. And so, first they take the time to define what is the severe domain. So, if you are thinking training zones, you have your threshold zone. And then above that up to the highest point that still elicits feel to max. So, people would think of this if you were looking at Doctor Coggins training zones, this would be his VO2 max zone, they basically define critical power, as the low end of that zone, critical power can be right around lactate threshold, often just slightly higher. And the high end of this, they had a tougher time defining it, but it was the highest intensity and the shortest duration that elicited VO2 max. And they gave two groups of athletes intervals, one group did, I think it was four min intervals at the low ends right around CP, just slightly above. The other group did intervals at the high end. But they used a percentage,of I think max time that they could do at that high intensity as the length of the intervals, meaning every athlete had a different length of interval. But if you look at the graphs of it, their intervals are right around one minute, somewhere in that range, kind of 30 seconds to one minute. And what they found was that group working at the very high end of that severe zone saw greater improvements in VO2 max and greater improvements in lactate threshold.

Chris Case 26:53
I think this reminds me of a conversation we once had about VO2 max intervals in quotes with Sebastian Weber and how kind of silly the name is because you essentially do one but you can’t do seven of them in a row. Right?

Trevor Connor 27:09
Right. Yep. So the five-minute VO2 max intervals. So if you did five by five, and you actually did them all at your VO2 max power, somebody would have to carry you home. Right?

Rob Pickels 27:20
Well, but not if you did that based off an inflated FTP, Trevor.

Chris Case 27:24
There you go. There you go. Okay, so back to this study.

Rob Pickels 27:29
So if I were to self-pace, I took a guess I said, Hey, you know, what? If I was gonna go out and do a four-minute effort right now, I’d probably do that at 125% of my threshold. And if I was going to do an eight-minute effort, probably do that about 115% of my threshold. I look back at my historical data.

Chris Case 27:49
How much history?

Rob Pickels 27:51
Years? No, actually, I look back at my past six months, because I haven’t been riding much in the past two months. So I had to extend my range a little bit. When I went back, it appeared that my four-minute efforts were typically between 120 and 125%. So I was maybe a little optimistic on that, but not too bad. And then my eight-minute efforts were between 112 and 115%. So I was pretty spot on there. but then I also looked at this for the participants, which was not necessarily easy, because they didn’t report the information for the participants. So what I did I actually out of the John Mackey study, which is pretty universal, I pulled a prediction of FTP out of the power max equation in there. And I applied that because they did report the power max of these subjects. And I took that on average. So in this current study, subjects, p max was 315 Watts, which means their predicted FTP was about 214 watts. That’s one thing to note, right? Because when we go back and we look at the subjects, there was eight, recreational, two trained, and two well trained in terms of ability. And so that relates to do we need expertise and self-pacing these or not so we’ll put a pin in that. But when we go back, and we look at the workload that they did, they did 261 watts for the four minutes on one minute off interval. That’s about 122% of FTP. That’s real similar to what I would have done. For the four minutes on two minutes off, so the longer recovery, there were 275 Watts, which is 129% of FTP, if anything slightly above what I would have done. On eight minutes on two minutes off, they were at 234. That’s 109%. So a little low, but eight minutes on four minutes off, they were at 250 watts, that’s 117%. So the takeaway from this is, even though these riders had no feedback for how hard they were going, they were not told their wattage. And given that they are recreational cyclists, eight of them, maybe that wouldn’t have meant anything to them. They were remarkably close to what I would have recommended for myself or for other people to do this at. And I found that one of the most interesting points of this study, that if you just unleash someone and have them go as hard as they can, for these four, eight minute efforts, they’re going to go about the right pace.

Trevor Connor 30:37
Yep they do show actual graphs of some of the intervals from these athletes. It says, mean response, so I think this was averaged out. As a coach who’s looked at a whole lot of these sort of intervals to teach my athletes how to execute it well, I would look at this and go, that was good execution, you did a good job here. Because you see that power in each interval come up to whatever level it is that they’re trying to sustain. It’s held pretty steady. And it’s pretty much the same across all four intervals. In all four cases. So I was actually quite impressive. If an athlete had sent me this, I’d go, that was a good workout you did well.

Rob Pickels 31:18
Yeah, I think oftentimes, what you would predict that you would see, right, Trevor is that that first interval looks real good, real high power numbers, and then they steadily decline thereafter, because you overcooked yourself on the first one. And they didn’t necessarily, I don’t know if that’s a part of maybe the training or familiarization session that they did. But execution on this was great. In that same graph, we also see the VO2 line, how much oxygen there they’re taking in and utilizing. And it follows again, another predictable pattern on the very first interval, even though the power the effort goes straight up to where it needs to be. VO2 lags behind a little bit, and they’re not reaching a steady-state VO2 really until the very end of that first effort. In the second effort, VO2 comes up a little bit faster and there may be reaching a steady-state VO2 about halfway through the effort. On the third effort. They’re reaching steady-state VO2 a third of the way into the effort. And on the last effort almost from the onset of the effort they’re at steady-state VO2. And I think that this lag period in VO2 is something that we need to consider. The author’s predicted that the four-minute efforts would elicit a higher power output and they were right, you’re going to go harder for four minutes then you will for eight. But they also said hey because that effort is shorter and the power output is higher than VO2 is going to be higher and therefore they’re going to spend a longer time at or near VO2 max. When I first saw this, I thought quite the opposite because I was thinking of this particular fact right that there is a lag in VO2. Therefore the eight-minute effort would have a longer time at VO2 max or thereabouts. Because the lag period is going to take up the first 2,3,4 minutes of that effort. And then you’re going to have an additional four minutes in the eight-minute total. You’re gonna have an additional four minutes where you’re riding right at that VO2 level, you add that up and you’re going to have more time at VO2 max. Trevor, what did they find in this study.

Trevor Connor 33:34
So I’m looking at the chart right now. And it was the eight by four minutes where you saw the greatest total absolute length of time spent at VO2 max, so they had 687 seconds. Now interestingly, the second-longest was the four by twos at 457 seconds, then the eight by twos at 364 seconds and the four by ones you saw the least length of time at VO2 max which was 284 seconds. But if you look at it as percent of the total time, you’d expect that because the eight-minute intervals you’re doing twice as much time and intensity. So if you look at the percentage of the session time that was spent at VO2 max, then it changes up a little bit the best were the four by twos 47.7% of the time spent at VO2 max. Next best was the eight by fours at 35.8%. Then the four by ones at 29.6%. And the lowest in terms of percentage. Were the eight by twos at 19% which I found pretty interesting. And the thing that was surprising to me was in both cases with both the four minutes and the eight-minute intervals, It was the longer rest periods that resulted in the greater length of time both as a percent and absolute time spent at VO2 max.

Rob Pickels 35:13
Yeah, Trevor, that recovery portion took me by surprise, too, right? I think that- I don’t want to say it’s common knowledge because maybe it shouldn’t be.- But exactly as you’re saying, if the recovery period is too long, and your ventilation comes down, then you just have to go through all of that ramping up again on the next interval. And that to maximize time at VO2 max, you want to have a relatively short recovery. Four minutes doesn’t feel relatively short to me, you know, to tell you the truth. But you know, I think that the takeaway is that that eight by four is, if we’re looking at just total time at VO2 max, you’re trying to get as much there in a session as possible, then we’re learning that the longer efforts are worth it. However, the four-minute, -especially the four-minute interval with a two-minute recovery,- there’s good economy there, right? Because it was a shorter effort, it was a much shorter duration for the workout, I mean, the workouts, basically half as long. And the percent of time at VO2 max was higher. And so if you have a few moments, you have an hour on the trainer, in between meetings now that we’re all on Zoom, then that’s the way to go. If you’re just looking to maximize your time at VO2 then the longer intervals are what’s going to do that for. I think if we go back and we look, Trevor, at the percent of their FTP, the eight-minute on two-minute off had an average workload of 234 Watts, that’s only 9% higher than their FTP. And it’s really the one that looks out of place compared to the others. So the highest percent was 129, then 122% of FTP, followed by 117%, those are relatively tightly grouped, and then that 109% really just sort of the bottom dropped out of it. Now, for the individuals, the rating of perceived exertion for all of these came out to be relatively the same. I mean, I believe that they use the six to 20 scale. And they were within a 10th of a point which is no difference really. So each subject rated or maybe not rated, they chose workloads that elicited the same rating of perceived exertion, because they were able to self-select, which I found really interesting, I thought that some of these would be harder than others. But I think that’s what we’re seeing here with eight minutes on two minutes off, that’s a long work, bout with very little rest. And so they lowered their workload themselves to achieve that, maybe it would have been more effective if they had been prescribed a workload, that was higher than that 109%. But that was not the purpose of this study.

Trevor Connor 38:02
But I did find that really fascinating the ability of these cyclists- and these were not professional cyclists at all,- to basically look at the protocol and find that power that allow them to essentially complete the protocol, complete the intervals, every time and feel like it was about the same difficulty

How Would The Results Look If It Was Performed By Professional Riders?

Rob Pickels 38:24
And do it well. Trevor, do you think that if we did have professionals or if this was, a cohort of highly trained cyclists or above, do you think we would have seen the same results?

Trevor Connor 38:38
Man, that’s a good question. Because I mean, I do look at those graphs and go, that was really well executed. That’s exactly what I want to see. So even in a pro, I’d want to see very similar execution. So I don’t know, my guess is you’d obviously see higher absolute power. But whether you would see the same differences between the different protocols, maybe in a pro, you’re getting into oxygen deficit and oxygen debt. And one of the big adaptations in pro cyclists is less of both. So it might be in a pro, they can handle the two-minute recovery much- or sorry, the shorter recovery. So the four to one ratio.- So the two-minute recovery on the eight minute or the one-minute recovery on the four minutes and be able to do the higher wattage where less experienced cyclists might need that longer recovery time.

Rob Pickels 39:36
Yeah, I think something like that would be a worthwhile follow-up to this, certainly. Another follow-up that I’d like to see as we mentioned before, I’d love to see 30-30s and see how that plays into this. Because the premise of that is the short recovery right in that work real hard for 30 seconds, take a very short recovery, work real hard for 30 seconds again. The dip in VO2 in those small recoveries shouldn’t be so much that you can’t eventually achieve VO2 max by the end of that. Does that play out given the information that we have? The other thing I’d like to see is a one to one ratio. The study looked at four to one, it looked at two to one. Can we take that one further? What happens if we do an eight-minute interval with eight minutes of recovery or a four-minute interval with four minutes of recovery? Is that really going to change the game? And I almost wonder if the if the four-minute on four-minute off situation, I wonder how strong that would be because you’d be able to hold a really high workload repeatedly for that and really drive very quickly up to that 90% and above of VO2 max.

Trevor Connor 40:46
Yeah. Now there only mentioned that was actually referring to Dr. Seiler’s study and so I’ll just read this. Similarly, Seiler and Hetfield had described slightly higher velocities and VO2 with two minutes compared with one minute active recovery during six four-minute repetitions in well-trained runners with no further increases when extending to four minutes. So that’s the best indicator that we have. So, the question I have for you, Rob.- And here’s the thing is this an honest question, or I just want to answer it.- This study gets into something that’s becoming increasingly popular and recent research of optimizing intervals is all about increasing the time spent at VO2 max, and what is your feeling about that? Is that really what we’re trying to accomplish?

Rob Pickels 41:42
I mean, I go for specificity on this. You know, I do believe but I’m not prepared to back this up right now, Trevor, because you’re springing it on me.

Trevor Connor 41:54
Don’t worry, I’ll answer it when you get it wrong.

Rob Pickels 41:55
I know you will. if I were to say, Trevor, I’d say that yeah, time at VO2 max, if we are looking to improve VO2 max, and time at VO2 max, you know, we need to exactly define what that is. Here, they looked at both 90% VO2 max and above and also 95% of VO2 max and above. But yeah, one would think that a greater duration in those workloads would lead to a higher adaptation. Right? We see this play out when we look across interval lengths at threshold when we look at them at base. And I would think it would compare here too.

Trevor Connor 42:38
I was desperately this morning reading that 2016 study. So this is an interval training in the boundaries of severe domain, because that’s what they were trying to get at is there any validity to this whole question,- at least this is one of the questions they had to this time spent at VO2 max,- and certainly those shorter, much higher intensity intervals they saw a greater period of time spent at VO2 max. And certainly saw greater gains in VO2 max and LT. So I would say this is an unanswered question. But there are indicators that your aerobic machinery is going to improve by maximizing that time at the top end of your aerobic metabolism. But I wouldn’t say there’s gonna improve all aspects of your training. And I’d say it’s still a question that needs to be answered.

Rob Pickels 43:33
Yeah, everything always comes back to limiting factors right? What is holding your VO2 max or your performance back. And there’s multiple things that fuel into that. You can get gains in VO2 max by large amounts of riding at low intensity or by shorter amounts of riding at high intensity. And I think that you would see a change in adaptation based on the needs of that individual. This is not the only way to improve your VO2 max, but I do think that we see oftentimes in less trained athletes like this that these VO2 intervals can rapidly improve someone’s VO2 max more so than we would see in a well-trained athlete.

Chris Case 44:27
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What Does The Inclusion Of Sprints During A Transition Period Do For The Rider?

Chris Case 45:24
All right, well, let’s move on to our final study of the day. This one is entitled, The inclusion of sprints in low-intensity sessions during the transition period of elite cyclists improves endurance performance, six weeks into the subsequent preparatory period. It is also in the International Journal of Sports Physiology and Performance. Lead author here is Madison Taylor. Not sure where this study is being conducted, which university it is. So inclusion of sprints in transition period. Trevor, do you want to give us the overview here.

Trevor Connor 46:14
So this is actually in some ways a follow up to a study that I really enjoy the Dr. Ronnestad did back in- I’m just pulling it up right now,- this is back in 2014, the study was called hit maintains performance during the transition period improves next season performance and well-trained cyclists. So the gist of this is getting at what happens in that transition period. So you just finished your race season, you’re now thinking about the next year, you’re not quite ready to get into full base mode. So you have this four to six week,- depending on the athlete could be longer, could be shorter -transition period, where generally even in pros, they’re just going to ride easy, they’re going to be unstructured before they get back to training. And the concern here is you see so much of a decrease in performance metrics, and physiological metrics, that they’re making the argument, the whole base period, or what they call the preparation period, is spent just getting all these values back. So you don’t improve. He’s just trying to get things back. So they’ve been looking for ways to without turning the transition period into full training, doing enough work to be able to maintain some of these physiological markers so that in the preparation period, you can actually improve your level. And they felt they found that in that 2014 study, but they were using some pretty hard interval work that these athletes had to do once a week. So the question with this one is if we just tack in some sprints into one of their easy base rides, can you see similar benefits with a lot less work?

Chris Case 47:56
And I want to be clear here because we so often talk about- and I know this is the offseason there’s a period where you want to set the bike aside if you’re a cyclist, or you want to put the shoes away if you’re a runner and do something else. – So the transition period is when you’ve gotten back on the bike or put the shoes back on, and you’re doing something, but the structure is not there yet. You’re just easing your way back in and they’re talking about introducing some sprints during this period. Correct?

Trevor Connor 48:34
Correct. And I don’t think in this case, with these pros, you have an actual period of time off the bike because remember, they did the first test five days after their final race of the previous season

Rob Pickels 48:45
That was the end of the Comp phase.

Trevor Connor 48:47
Yeah, so it’s pretty much they went from competition right into this transition phase, there was not time off the bike.

Chris Case 48:54

Rob Pickels 48:56
But that’s just related to the methods of this particular study. You know, the application of that, I think across the layperson, there’s potentially a benefit, Chris, as you’re saying to take some time completely off.

Chris Case 49:10

Trevor Connor 49:11
I’m personally very big on that. I think of this as this is what you should be doing, say, very late October, early November for that first month before you get back to that full training and maybe at some point in December.

Chris Case 49:29
Alright, so Rob, do you want to take it from there and tell us a little bit more about what they found?

Rob Pickels 49:34
Yeah, I think that there’s a few things to unpack from this 1) we are talking about elite cyclists at this point. We have an average VO2 max of five and a half liters in a relatively small person about 160 pounds on average, about 73 kilograms. As Trevor mentioned before, this initial testing was immediately after their last competition and so presumably the riders are at their peak at that point in time, right? I mean, granted, they might have had a little bit of acute fatigue from that particular competition, whatever it may be, but physiologically, they really should have been at the top. So I found that a really interesting comparison. Now in Trevor’s opening, he also mentioned that, during this transition period, riders lose a lot of fitness. But in this particular study, they did two groups one included the sprint intervals, and the second was a control group that didn’t, they only did low-intensity training. They decreased their training by 64%. So one group did only low intensity, that group, they only lost 1% of their fitness parameter, and to quantify that they had riders do a 20 minute time trial so that plays back into the first study that we covered today. And that low-intensity only group they lost 1%. Now the group that did the sprints and these sprints- this is not an easy workout, when when I first saw sprints I was thinking Oh good 10 seconds, that’s no problem.- They did three sets of three by 30-second sprints so 9 30-second sprints which in my opinion, that’s quite taxing for one particular workout. Although throughout the course of a week, it’s not so taxing, you know that you’re going to be fatigued really from that anyway. Those riders the sprints, they actually gained 7% improvement in that 20-minute test. So you took riders who decreased their weekly volume to 64%, included 9 30-second sprints and we’re actually 7% better than when they should have been at their peak, which I found almost baffling. I did not see that coming.

Chris Case 51:54
Right, sure.

Trevor Connor 51:56
So one of the things I found pretty shocking in this study,- going back to this is not easy stuff. And this is a study they could only do with pros- So they did this test with these pros, three times. So once at the end of the competition period, one after the intervention period, and then six weeks into the preparatory phase. The test protocol was a warm-up, then a lactate test, where you do five minutes stages to determine your lactate threshold, then a 10-minute recovery. Then a VO2 max test, which is- oh we are only halfway through-

Chris Case 52:36

Trevor Connor 52:37
Then 10 minutes easy. Then 35 minutes at 65 or 68% of VO2 max then four repeats of a 32nd all-out sprint with I think four-minute recoveries, then a six-minute rest. And then you do the 20-minute time trial.

Chris Case 52:57
What the heck Wow, this is a big day.

Trevor Connor 53:01
That is a huge day. I mean, I have done the lactate test and the VO2 max test in the same workout and left that going Damn that was tough.

Rob Pickels 53:12
Ready for lunch after that one.

Chris Case 53:14

Trevor Connor 53:14
Right. And here, you’re only halfway through it.

Chris Case 53:19
Wow. Okay.

This Study Offers More Questions Than Answers

Trevor Connor 53:21
So that was fascinating. But what I found really interesting in the results was you certainly saw this improvement in the 20 minute time trial in the group that did the sprints but you saw no other improvements. VO2 max did not improve, general efficiency did not improve, watt max did not improve, no other measured variables improved, except for just that ability to do that 20-minute test a little harder. And interestingly, there you saw in that group, the sprint group, they were doing that 20-minute test at a higher percentage of VO2 max. So they measure their VO2 during that time trial. So what I get out of this was they weren’t any fitter, they just had an ability to go a little harder.

Rob Pickels 54:19
I reached way back into a Basset and Holly study. And, you know, if you really break down that endurance performance, you can look at economy. And then the other major determining factor is is the VO2 at threshold. Two things play into that your VO2 max and then the percent of that VO2 max that you’re at, at that threshold workload. And that’s the change that we saw here right these riders in the sprint group had a higher VO2 during that 20-minute trial and a higher percent VO2 max, does that indicate that something changed within them that they were able to do that? Or is that just indicative that they went about this trial in a slightly different manner or in a more rested state. As Trevor said, we didn’t see any other parameters of improvement, their workload at four millimoles of lactate didn’t change. The sprint performance among these groups didn’t really change. I believe the sprint group had a tendency to improve 30-second sprint performance, but it was not statistically significant, which I found fascinating there. And so I almost come out of this with more questions of why. I think that we understand that adding efforts like this into a bass ride, more than one study has shown that they have positive benefits. I don’t know that we truly understand why the heck that is, at this point, the 20-second effort ought to be primarily an anaerobic or neuromuscular effort at that point, depending on the workload that somebody is doing it at. Why would that improve your endurance ability, which should be primarily anaerobic effort, if we do back up to the earlier study, there is some anaerobic contribution into these 20-minute efforts. But at the same time, these riders shouldn’t really be seeing an improvement in that because you would think that system would be firing on all cylinders at the pretest at the end of their competition phase. So I almost leave this with more questions. And, that doesn’t make it bad research or a bad study. It just leads us to say, hey, how do we really understand what the heck is going on here?

Trevor Connor 56:32
Well it is a really interesting question, and you look at the previous Ronnestad study, where they used high-intensity interval, -so full interval workout once a week to expolore the same sort of thing.- And in that study, you saw an improvement in LT. So specifically, they were looking at power at four millimoles lactate, this study, no improvements in power at four millimoles lactate and that other study there was. So the other study, you are actually seeing some sort of physiological improvement. Unlike this one, none of those parameters improved. So I agree with you, it almost raises more questions than answers. The best guess I have is that transition period, they basically got some rest, they probably finished the competition period, pretty cooked pros race pretty long, hard seasons. So probably didn’t do that first test at their best. They had three weeks to basically recover, but the sprint workouts was doing just enough to maintain their ability to just hurt, to just suffer. And so you didn’t see it really maintained anything physiological, they just could hurt a little more they were rested. So maybe able to do that test a little bit harder. That’s, that’s the best guess I’ve got.

Rob Pickels 57:52
Yeah, you know, we do also know that intensity is going to preserve fitness more than low intensity is going to and, I worked under Neil Henderson for years. A guy that traveled quite a bit and maybe still does, and he would say, hey you know, when I’m on the road in the hotel, I get on that exercise bike, and I start out one minute, easy, another minute, a little harder, another minute, a little harder. And in 10 minutes, you know, I’m going all out at the end in the hotel sort of gym. And that’s what he did to maintain his fitness when he was on the road and also still trying to race competitively. And that theory looks like it’s carrying over into this.

Trevor Connor 58:32

Chris Case 58:34
Is that the message for amateurs to take away from this study? What is it? Is there anything?

Trevor Connor 58:40
Yeah, that’s a really good question. My message because of what I took from this,- and look, they even said in the study, I’m reading right from the study here, in the conclusions,- quote, as they could have been more specifically trained to tolerate this type of stimulus. Talking about that sprint group. My feeling is doing those sprints in the transition period isn’t doing much for you physiologically. So I’m not sure there’s a huge benefit to that even though they conclude that there is. I do think it says something about using sprints to build your ability to tolerate hard efforts,

Chris Case 59:22
It’s more psychological in a sense.

Trevor Connor 59:24
And they raise that and actually raise the broader implication of should you be doing some sprint work during the taper? Because again, it’s what you’re saying they should have been at their fitness at the end of the competition period, but maybe they were tired. So essentially what they did here was a giant taper and the sprints are just enough to keep that ability to suffer and hurt and being rested, they were able to perform better.

Rob Pickels 59:49
Yeah, for me, you know, a taper is a reduction in volume but a maintenance of intensity for exactly this reason, and I think that anybody who takes intensity out of their weekly workload you suddenly feel very flat when it comes time to really perform.

Chris Case 1:00:08
Very good. Anything else guys? You didn’t really fight today, I was expecting more.

Trevor Connor 1:00:17
We had some good insults

Chris Case 1:00:20
Ornery? No. Illuminated today Rob Pickles? Yes. You were illuminated.

Rob Pickels 1:00:26
Sometimes Trevor’s so right you just have to agree with him.

Chris Case 1:00:30
What a nice thing to say.

Trevor Connor 1:00:32
I feel like I have to insult you in return now.

Rob Pickels 1:00:36
Gotta keep balance in the world.

Chris Case 1:00:39
Until next time.

Chris Case 1:00:47
That was another episode of Fast Talk. Subscribe to Fast Talk wherever you prefer to find your favorite podcasts and be sure to leave us a rating and a review. The thoughts and opinions especially Rob’s on Fast Talk are those of the individual. As always, we’d love your feedback. Join the conversation at to discuss each and every episode. Become a member of Fast Talk Laboratories at To become a part of our education and coaching community. For Rob Pickles and Trevor Connor, I’m Chris Case. Thanks for listening.