Is Zone 2 Overhyped? (for recreational & amateur cyclists)

Zone two training for recreational cyclists. Are we doing too much? That is the topic for today's podcast.

Science linked below. 

Why Zone 2 isn't the best focus for recreational cyclists

https://link.springer.com/epdf/10.1007/s40279-025-02261-y?sharing_token=_JBa16c0TVKpWC-ASGX5qfe4RwlQNchNByi7wbcMAY4Y3tM2wPWWmLYbv6lMcE-pH5K9vrfirQVzyWj5WcLQybc2o6nv6PXysP1Xo-j-QTDsrlCeVJ9oswxeS9e2PpwHVOZNvzJZ7MKKxr9P1f7alhZiBvYFi_CeRlJIju9dpZ4%3D&fbclid=PAZXh0bgNhZW0CMTEAAafCOwx6qpiWJzyo8YhUGj1EQL0fd3AWgnO8HbEQ92gjgT3p867-QzySTggs0g_aem_nhDD20Ez4njrNk0hghZ4Hg

 

Defining Zone 2:

https://journals.humankinetics.com/view/journals/ijspp/aop/article-10.1123-ijspp.2024-0303/article-10.1123-ijspp.2024-0303.xml

 

Full Transcript:

 

Cam Nicholls (00:00):

Welcome back to the RCA podcast where today I am joined again by the RCAs data nerd Ben Treble. And Ben selected today's topic, which is about zone two training because he thinks it's a little bit too hyped in the recreational and amateur world, which I understand why, but I'm, we're going to have a little debate today because I think, I believe the other way. I don't think it's hyped enough, but Ben is the science guy and I'm not. So this could be an interesting discussion because he's got the evidence to back up what he's got to say. So Ben, do you want to just start us off by explaining why this topic has come to mind?

Ben Treble (00:41):

Yeah, thanks Cam. It's been in the back of my mind for a while. I think there's a lot of marketing hype and the marketing companies and product companies jump on trends very quickly because that's their job. And I'll caveat this and say I'm not an anti zone two person, but I think we kind of forget where it comes from and we quickly lose the context of where did this kind of originate the idea of doing zone two and some of the research on where it comes from. So this is how do we critically analyze the research where it's come from and understand how that might apply to us as individuals because we're all different, right? A recreational cyclist is very different to an elite level writer who is doing much greater volumes of writing. What peaked the topic though was very recently there was a narrative review in the journals that came out from, I want to try to pronounce it correct, stor Etal. It's called Much Ado about zone two, and they did an article that really looked at assessing zone two's ability to improve mitochondrial capacity and cardio respiratory fitness. So we're making an assumption that the reason we're doing zone two training is to try and improve fat oxidation and improve mitochondrial capacity, these things. So if we run on that assumption is zone two training the best thing to do for recreational athletes and the general population and the narrative review looks at a lot of research and ultimately says no.

Cam Nicholls (02:21):

Wow. Okay. And before you continue and explain why it was a no, can we just define zone two for the purpose of this podcast? Because I'm just conscious it can be confusing at times, particularly if you're looking at a scientific model where there's only three zones and zone two is more like your sweet spot sub-threshold. When we talk about zone two, which is predominantly what it's referred to, but just to make sure we are clear, what are we talking about?

Ben Treble (02:54):

Yeah, I think we're referring to it more in the five zone model in most cases that people think about it. So it's an easy talkative pace If we're thinking more about RPE sort of scales, it's a very easy conversational intensity and the end goal typically, like from a scientific point of view, for me, the reason I would ask people to do zone two training is we're predominantly trying to improve the aerobic capacity and predominantly trying to improve our ability to maximize our fat oxidation.

Cam Nicholls (03:32):

And I think in a lot of people are used to power. So in a five zone or six zone or even a seven zone model, it's typically around 55 to 75% of functional threshold power if you're using power. Is that right?

Ben Treble (03:49):

Somewhere around there, potentially somewhere around there, around anywhere from 50 to 65, 70 at the high end I would say is getting closer to a tempo at that

Cam Nicholls (03:59):

Point. Okay, so why was it a no for recreational and

Ben Treble (04:05):

Amateurs? Yep. And for the record, this narrative review defined it as below lactate threshold one, which would be zone one in a three zone model for those listening and using a three zone model with lactate thresholds, the answer was a no, and it's because the comparator was against doing high intensity work and looking at, so the narrative review looks at a whole lot of research that's out there and says, what's improving these capacities predominantly like mitochondrial density, these sort of zone two physiological adaptations we're targeting what training best improved them. And it wasn't zone two training that improved those outcomes. It was high intensity interval training, and it was varied, like different studies of different types of zone two that could be VO2 efforts, hit sessions, all that high intensity interval work always resulted in better outcomes and adaptations that we typically associate with zone two training that when I talk to people about doing zone two training, that's what they're trying to achieve with it.

Cam Nicholls (05:15):

So from what I understand, when you tip into that threshold territory when you're training, you start to shut off adaptations that you can achieve if you're just in a zone two state. So therefore, if you're predominantly focused on high intensity interval training, like you talked about VO2 max training or it could be sprint training or threshold training and you're not ever really going out and predominantly working at that aerobic level, does it mean that you're missing out on adaptations or you're still going to achieve those at a VO2 max diet or at a threshold interval state?

Ben Treble (05:58):

Yeah, I think it's a good question because it outlines one of the challenges in, I would say there's short, medium, long-term development of all of these capacities. And in many cases the research is fairly focused on short and medium term development. Like we're looking at research studies that do hit intervals for six weeks and compare that to the group that did endurance training or eight weeks, 12 weeks. Very rarely do you find groups doing longitudinal studies that do this in a controlled fashion more than three months, right? Because the cost and the resource, trying to find participants to do that and stay in the study is very, very difficult. So keeping that context in mind, that's probably where the HI training is going to give you the fastest short term development of all of these capacities because even when you do hit training, you're going to have the warmup. The cool down there is still a lot of time spent in those low zones.

Cam Nicholls (07:07):

And that's what I always thought. I feel like people when they look at say the 80 20 principle of the polarized model, which is where people are like, oh, well if I've got to do zone two training, I've got to do the 80 20, which is polarize and pyramidal has become more prevalent these days, which is more like a 70 30 or somewhere around there, but you're still spending a lot of time in zone one and the three zone model, which is a lot of time in zone two, which is what we're talking about today. But I think a lot of people get confused. They think, well, if two of my sessions are zone two focused and three high intensity interval training focus, then I'm doing too much high intensity interval training. But when you break down those high intensity interval training sessions individually, you go, well, I'm spending 20 minutes writing out to the hill where I'm going to do my intervals in zone two between each interval I'm in zone one, and then on my way home I'm in zone two. So even those high intensity workouts in themselves, proportion wise, you're probably spending a lot of time in zone two or zone one

Ben Treble (08:22):

Significant, and it's underestimated. So it's a very good point. One I'm quite passionate about, and this comes back to something I said earlier around, I think there's a bit of a misinterpretation between the science and where we see all the marketing hype around zone two, which is, let's take the 80 20 example with polarize, which is great in science, you would often either use, it's called you measure a session, you would say there's a goal in session approach, which says if this session is VO2 intervals, it gets classified as a high intensity hard workout. The other approach that most science follows is overall relative time spent as a percentage in the zones. So if you take, for example, you get a group of people to do sprint interval training or short high intensity intervals, and they do three sessions a week of just these intervals with a warmup and cool down, when you really add all of the time up together, it will come out as polarized. But often exactly as you said, I've seen recreational or amateur cyclists say, oh, the 80 20, so if I'm doing five rides a week, two of them should be intervals and three should be zone two easy. That's not going to give you the best outcome. And it's not a polarized distribution as in what gets taken away from the research. So you're not going to get the same outcome. They're totally different things.

Cam Nicholls (10:00):

So therefore people need to more specifically look at their total work time versus the workouts as what they're doing in the workout and they'll have more effective outcomes as a general blanket. Of course, it depends on what you're training for, but we know a lot of recreational and amateurs are looking to roll more turns in the bunch. They're looking to increase their FTP, they're looking to beat their mates up the local climb. So as a result of that zone two training as a foundational tool will help, but not as much as your high intensity interval training sessions.

Ben Treble (10:36):

I think sometimes we forget some basic principles and we overcomplicate things. The way our body works is we have to stress it to cause adaptations and we get the adaptations from the recovery. So if we're just doing super low intensity work, you're not going to create a lot of stress on the body that's going to create a lot of adaptation. So the question is where did the zone two training come from? This is maybe it's a view of my own, not the one that everybody would necessarily share, but I would look at training a bit more from the perspective of how much time do you have to train and how much energy expenditure is available and how do we recover from that? How much time is there to recover from this? And this is a better determinant of how much work can the athlete take on? And that's where we start to build a program out. When you think of elite athletes, when we do high intensity work, we use a lot of glycogen, which is one of our limited resources, right? In a 90 minutes session, like super high intensity session, you can pretty much burn through your full glycation stores, 90 minutes to two hours, you'll burn through your full stores and it will take most people on average 48 hours to fully replenish them.

(11:57)
So if you think about everybody's limiting factor of 24 hours a day with seven days a week, you can only fit in two to three super hard sessions a week. So what do the pros do with all the other hours? Low intensity work and high volumes of it, there's nothing else to do. So of course they're getting massive adaptations, but they're already doing the maximal level of high intensity work that we can from an energetic point of view tolerate. So if you get someone who's only got six hours a week to train, if you said spread them out and you do three, two hour sessions of hard efforts versus someone who just does one hard effort session with two easy ones, I would expect you get much better performance outcomes from the guy doing the high intensity stuff all the time. Now that's not factoring in, especially with recreational athletes, can they recover and mentally handle that training load, right? So that's the individualization piece that's again, often missing from this marketing media scientific conversation.

Cam Nicholls (13:09):

What I've often seen at the RCA in the past, we've had the recreational that comes to us or amateur, and they've been doing roughly 10 hours a week. They've been doing very little zone too. They've been doing a lot of tempo because tempo feels like they're doing something Zone three, maybe like 80, 85% of FTP, that's where they love to sit, particularly when they're riding side by side with the mate and they're half wheeling each other. They might be doing some bunches, so they're taking their heart rate to max two or three times a week and they might, they call it a social spin on a Friday, which ends up, they're still doing 400 watts up the hills and they're coaching down the other side. So you actually look at what they've been doing for the past 6, 12, 18 months more and it's just been all intensity.

(13:57)
So what I've seen worked well as a coach in the past. I don't coach anymore as you know, and maybe I had this wrong, but I saw, and this is where I'm going to debate you a little bit, but maybe you'll agree given the fact that I'm presenting this context of this persona that we go, alright, you're not in a rush to achieve your goal, which is to take your FTP from 250 watts to 300 watts. That's a very common goal. Everyone wants to hit that next 50 watt mark in their FTP. So let's spend the next six to eight weeks just getting rid of intensity and we're just going to focus mostly on aerobic work. We'll do maybe a bit of tempo, but we'll do a lot of zone two stuff. So you've got eight to 10 hours a week and we're just going to sit at zone two.

(14:49)
And what I've found this to do is number one, it freshens them up. So they probably need a bit of a bout of away from max heart rate away from intensity. Let's just give the muscular skeletal system and your mental capacity a bit of a rest. And in doing so, they seem to cultivate different adaptations. And the big one that I see when I've done this with members is you might get them to do a zone two ride. So 65, 70% of FTP on the trainer and they look at what their heart rate does and their heart rate will drift by 10, 15 beats in this one hour ride and their heart rate will be quite high. And then if they spend that six to eight weeks specifically focused on this zone two training, you get to the eight week mark and all of a sudden they do the same ride on the trainer, 65% of FTP, their average heart rate dropped about by about 10 beats and their drift is maybe three or four beats over the one hour versus the 15 beats.

(15:56)
It was at the start of the process. So you're like, wow, this person has really, there's something physiological that's happened in their body for their heart rate to drop significantly and drift a lot less. And my understanding from that was, well, they're no longer getting a rise out of the lactate system so they can focus on aerobic adaptations, they're increasing their lung capacity, they're stretching their left ventricle, they're boosting mitochondrial function. What is it? The red capillary network is enhanced? All these things have occurred. So is there truth to that or was I just feeding into the marketing zone two hype at the time four or five years ago?

Ben Treble (16:44):

My first thought would simply be that most likely they never were getting enough recovery. Like most amateurs like you, I think are the same experience. They come to you, they have this sort of a lot of social rides, but they often, one, don't have enough recovery within the week from those moderate hard rides that are mixed bags, let's call it. And they don't have enough recovery week on week, so there's no periodization. It's not like they build up for three weeks and take an easy week or do a specific block and have a week off. And I think very simply by just doing what you said, taking someone from that first baseline into just having some easy rides throughout the week that's targeted would give them recovery from the hard rides and they would see adaptation from this and feel better for it. That's my initial reaction. So it's not wrong, but I think that's why they would see the benefit, which comes back to how much ability does athlete have to recover within their context and how much can they tolerate in terms of high intensity work.

Cam Nicholls (18:00):

So in an ideal state, if somebody's coming blank canvas and they don't have these bad habits and they're not in a fatigued state, then using a combination of high intensity interval training two to three times a week with some zone two ride splashed in there, mainly used for recovery and also to keep your consistency going will foster the best outcomes from an aerobic adaptation perspective.

Ben Treble (18:32):

And there's a key factor here. You still get some amateur riders who do larger volumes,

(18:39)
True and riders develop only recreational riders might come in and start by doing four, six hours a week, fall into the sport quickly, and within a few months they're doing 10 hours a week or more. And so at some point you have to adjust this, right? So this idea that you could only do high intensity work sort of prevails when you're doing two or three sessions a week and that's it. But once you start doing long rides on the weekend and this volume is getting greater, you have to start factoring that in. How much recovery do you need from those and how much recovery do you need from the high intensity work to make sure when you get to the next high intensity session, you're able to do it at full capacity?

Cam Nicholls (19:21):

Interesting. And I also think once people learn how to do zone two training, because a lot of people think that they're doing it, but they're not. I've got a friend here on the Sunshine Coast and I've told him 130,000 times now how to do it and he'll go out and we'll go ride together and I know he can't do it, it's not possible and we'll get back and he goes, oh, that was a great zone two ride. And I'm thinking to myself, not in an arrogant way, I'm just thinking that's not a zone two ride, Matt, why? Because we've got some little rollers here. Every time we get to a roller, he gets out of the saddle and he's going over threshold a hundred percent and he rides away from me. And then when we go down the little rise, I'll catch up to him and go past him keeping the pressure on the pedals.

(20:07)
I'm staying in that zone two state, whereas he will be free peddling a little bit, probably in zone one. So he's in and out of, he's jumping either side of zone two sometimes in zone two. Whereas if you can actually learn how to do it properly, I feel like it's a different experience. So if you go out and you sit at 60 to 65, 70% of FTP and you don't have traffic lights and you can be there for a solid one to two hours, you actually get back from the ride and you're like, oh, I actually feel not fatigued. I'm not getting into the afternoon period and feeling like I've actually done something really physical and it feels kind of like a different physiological feeling after a zone two, unless you do five hours of course, then it's going to fatigue you. But if it's just one to two hours and it, it's a different physiological feeling.

(21:05)
And also once you perfect it as well, I found this with a lot of recreationals, I actually really enjoy my zone two rides. So I'll go out and I'll do two hours down the coast, there's some rollers, but I'll basically stay in zone two for 98% of the time and I just really enjoy that type of riding. So there's a practical side to it as well. Once people learn how to do it properly, it gets them out on the road more, they enjoy doing it more, and as a result of that, they're going to ride their bike more. And as you said then if they're factoring in an extra two or three hours a week, it becomes relevant.

Ben Treble (21:43):

I think I would always still bring it back to what is the goal, what are you trying to achieve with the session? And don't say, oh, it's the zone two, but what do you mean by zone two? Because everybody has a different, even with science, there's different definitions of zone two. There was a paper that tried to sort of bring it together and come up with a cohesive definition of zone two. And when you look at that definition, which is sort of more related to trying to optimize fat oxidation and mitochondrial genesis and a few things like this, capillary density, the typical way to track your zone two doesn't. The reason it's very complicated is because most people use FTP and A percentage of FTP to work out their zone two, and this is where this creates problems in itself because zone two is not correlated very well to your maximal fat oxidation intensity, and it varies greatly between say, fit and unfit, less fit rider.

(22:54)
You hear the crazy stories of Char doing his high aerobic sessions, like three hour rides at 300 and I can't remember the number that was quoted. It was like three 40 or 360 something crazy, but for him it's sustainable because his ability to use fat for fuel is so high. The ceiling of that threshold is much closer to his VO2 max than you and I. It's also why he's such an incredible rider. It is just such a well developed and his genetic predisposition is so high to being in good fat burner. He can sit at that super high intensity for a very long time, but that is not his zone two by the rest of our definitions, right? By definition, if you use percentage of his threshold, it's going to be a lot lower than three 40 or 360, whatever the number was that he's doing his zone two rides in and he does them in intervals. You often find the pros are not doing, because their fat oxidation level is so high, they can't do it literally for six hours straight. They do it in intervals. They might do three by 60 minute, so three one hour intervals at their AET or Fat max intensity.

(24:13)
They've got a lot of carbs, so they still have to fuel these kinds of rides heavily,

Cam Nicholls (24:21):

But they've got all the tools that enable them to identify and pinpoint exactly where to go. So as amateurs, we've just got to go, alright, well 55 to 70% of FTP or 75% of FTP what feels right? And that's why obviously working with the coach is going to help you look at the data and obviously our next topic, which is looking at heart rate and correlation to power to see what actually happening physiologically while you're actually riding it, what a so-called zone two level. But I think for a lot of recreationals it comes back to they hear about it, they start doing it, they're probably not doing it properly on many different levels, obviously at a scientific level, but even at just a general stay at 65 or 70% of FTP for as close as you can for as long as a ride as possible, a lot of 'em struggle with even just that with road undulations and getting excited by chasing someone down the road and things like that.

(25:22)
But I think once they learn about it and they start doing it and they see the benefits of not going out and pushing themselves and coming back in a different physiological state, I think the key is not to over index on it and think about it as an 80 20 principle in terms of the amount of rides that you're doing, but more so how can you effectively leverage it in your overall plan work out to work out? Because you want to focus as per this paper, which you referenced at the start, most bang for buck provided you recover properly is going to be your interval work.

Ben Treble (26:07):

Yep.

Cam Nicholls (26:07):

Yes,

Ben Treble (26:08):

Yes. Key takeaway for me, high intensity work still prevails. We have to stress our body to cause it to adapt. This requires though good recovery and everybody is an individual with different contexts. If you want good training long-term, you have to stay motivated. And so for some people, that means there's a trade-off between having the most scientific efficient program for one that they're going to be more consistent at because the one they're more consistent at will get them much better long-term gains. We know that having long-term consistency at training, reducing illness and injury will always, in the long-term, give you the best outcomes than having the most scientific program.

Cam Nicholls (26:58):

So really it's about prioritizing your interval work and using zone two as potentially your recovery work. If you've got the available training time provided it's not a five hour zone two ride because that can be fatiguing.

Ben Treble (27:14):

Very,

Cam Nicholls (27:16):

Yeah. Cool. Well, we'll link the research paper in the podcast description. If you're keen to start implementing some zone two training specifically and also some interval work, something that's going to be specific to your goals, whether it be FTP or whether you've got an event coming up, make sure you check out the RCA website, www.roadcyclingacademy.com. Check out one-to-one coaching where you can work with Ben or one of our other coaches. We'll catch you in the next podcast.

 

 

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