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Road Cycling Academy PodcastAuthor: Ryan Thomas & Cam Nicholls
Interviews with top performing cyclists and industry experts in the fields of coaching, advanced training techniques, and human physiology. The purpose of this podcast is to learn and understand what makes high performing individuals tick, digging deep into their ingredients to success both on and off the bike. Language: en Genres: Health & Fitness, Sports Contact email: Get it Feed URL: Get it iTunes ID: Get it |
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Indoor vs Outdoor Cycling: What the Research Really Says
Episode 76
Tuesday, 14 April, 2026
This episode explores the differences between indoor and outdoor cycling, examining research findings, muscle activation, and practical tips for optimizing indoor training. Hosted by Cam Nicholls with expert insights from RCA coach Ben Treble, it offers valuable guidance for cyclists aiming to improve performance and understand the nuances of training environments. Stannards: https://stannards.com.au/ RCA: https://roadcyclingacademy.com/ key topics Indoor vs outdoor cycling differences Research findings on power output Muscle activation during cycling Practical tips for indoor training Equipment and setup considerations Chapters 00:00 Introduction to the episode and guest 00:27 Why are we discussing indoor vs outdoor cycling? 01:20 Research insights on indoor vs outdoor power output 02:09 Adjusting power zones for indoor training 03:00 Power meter differences and calibration 04:19 Key research findings on power output differences 06:43 Muscle activation differences between indoor and outdoor cycling 08:01 Summary of research and individual differences 09:52 Variability in power output and environmental factors 11:42 Practical tips for indoor training setup 14:07 Why indoor feels harder and how to adapt 16:44 Muscle activation and fatigue in indoor cycling 19:52 Key takeaways for indoor training optimization Transcript: Cam Nicholls (00:01.804) Welcome to the RCA podcast designed for recreational and amateur road cyclists with a focus on performance. We dive into cycling training, nutrition, strength training for cyclists and even bike fitting tips all designed to help you train smarter, ride faster and hopefully tear your mates legs off. So without further ado, let's dive into today's episode. Cam Nicholls (00:27.746) Welcome back to the RCA podcast where today I'm joined by RCA coach Ben Trevill. We're in a hotel room in Sydney. Why are we in a hotel room in Sydney, Ben? What are you doing here? Ben Treble (00:38.411) I'm here supporting the RCA Pro Velo League team for the Sydney Harbour City GP races. Cam Nicholls (00:45.602) You're doing the DS, the director's sporting. Ben Treble (00:47.667) Yeah, filling in for Ryan who's getting on the pedals. Cam Nicholls (00:51.308) Yeah. And I'm here attempting to make some content and I thought we'd use this opportunity to get together face to face and, you know, talk about some relevant topics for the audience training related, of course. The first one that I wanted to talk about is indoor versus outdoor cycling and the differences in, I guess, sensation and power output. Because I know a lot of RCA members that I've dealt with in the past and I know that you deal with do... tend to not struggle more, but they feel it's a little bit more difficult on the indoor versus the outdoor. But Yona, you've had a look at the research and the research may suggest something a little bit different. So I wanted to dig into that and hopefully we can come to some sort of conclusion at end of this discussion. I'm not sure if we will, but what's the research telling you when it comes to indoor versus outdoor? Ben Treble (01:41.486) Yeah, I think I will start by saying often when we look at research to practice, we find differences. So yeah, in practice, it's exactly what I felt personally, the feedback I get from my writers, what you've heard is that yeah, indoor training feels harder and it's kind of the perception that people even go as far to say you need to test indoors and outdoors and have different thresholds for indoors, outdoors and different zones or down adjust your zones by 5 % for indoors, for example. Cam Nicholls (02:09.198) Is that what you do with your members? Ben Treble (02:10.765) I do not know. Okay. If they need to down adjust it a couple percent for a certain session, like I'm not against it if it means they get through it, but generally, no, I don't set up separate zones for indoors outdoors. would only be if someone said to me, I'm going to do three months entirely indoors, or I want to do Zwift racing. That was their main goal. Then I would test indoors, train indoors and set zones based on indoors. Cam Nicholls (02:35.598) Okay. And what about the, this is a kind of like a, I guess a side note, but quite often, you know, people using different power meters as well. And, know, there will be even outside of the fact that the sensation feels maybe a little bit more difficult on the indoor, the indoor trainer reads a little bit lower as well. You know, like the kicker trainer or the indoor bike versus, you know, the Asioma power pedals, it might be 10, 15 Watts. So what do you do surrounding that? Ben Treble (03:00.888) first tip I give athletes when I have an onboarding with them and we chat about equipment is do you use your kicker's power meter or your trainer's power meter or do you connect your bike's power meter and use that as the power source when you do indoor training. that's what I would ask my athletes to do because then they want the same power source, you want to use the same power meter, indoors, outdoors. Where that's getting tricky though is a lot of people are moving to these sort of the Wahoo indoor bikes and the Zwift indoor bikes. Cam Nicholls (03:27.896) Got one myself. Ben Treble (03:28.78) where, you know, unless you're going to swap over your Asioma pedals or something, yet you don't get that choice. So it's important to know there are differences in power meters and a couple percent when you're doing high intensity efforts can make a big difference. Yeah. Cam Nicholls (03:42.062) Okay, so the conclusion of that is ideally use the same power meter if you can, if you can't know what the differences are and adjust accordingly. Ben Treble (03:48.782) Absolutely. So back to research, I sort of assumed I was just going to search the journals and find papers that prove that indoor and outdoor there's differences and we should have different thresholds. Fully aware I would have confirmation bias that that's what I was looking for. It's not what I found. So I was a bit surprised. Caveat, again, there's not actually a lot of research on this topic and I've only spent probably half a day digging. So there's probably a lot more out there still. But from what I found, there's a paper, a lot of people have, you we've referenced in our newsletter in the Cam Nicholls (04:17.3) Seems to be the main paper people point to. Ben Treble (04:19.214) Exactly. There's a 2022 paper from Lipski. There's two points I find interesting in this paper. One, they looked at mean maximal powers and threshold tests, indoors versus outdoors. That's probably the main component of the paper. They only looked at males. It's a small sample size. I think it was 12 and they're elite, you know, essentially world two or level athletes. So, pretty specific population group. And they found differences where... they could do better power essentially outdoors than indoors. There was a significant difference enough where they would say, yeah, this is worthwhile looking at. I think it was about 20 Watts, give or take. Cam Nicholls (04:53.39) Is it around 20 watts? Cam Nicholls (04:58.072) I'll pull it up while you keep talking then. Ben Treble (04:59.822) Yeah, so the two points I really wanted to touch on, one, the population group people need to be mindful of. It's probably not relevant to 99 % of our audience. Cam Nicholls (05:08.418) Yeah. Amateurs and recreational pro athletes. 19 watts. Ben Treble (05:11.294) Absolutely. Yeah, 19 watts, which is measurable and that's fine. But I think this is the next bit. When you dig into that paper, there's a statistical piece of analysis that they used, which it's appropriate, but I don't know if it's appropriate when we know this is high performance in small samples where individual differences matter. So we always say these people use group mains, for example, in this paper, what they did is they used a trimmed main. And they used a pretty high percentage of trimming, 20%, which means that they cut out the top 20 and the bottom 20 % of data points and their group means are only based on that middle 80%. Now, I know I looked at individual responses out of the 12, two of them did better indoors, but those data points got cut out because of the trimming. Already, if they had used total group means, like you would have had a different outcome. So, this is... Cam Nicholls (05:53.153) Okay. Wow. Ben Treble (06:04.248) just a bit of a mindful thing, I think, for people when they quote. This paper gets quoted a lot and like all papers, you get a lot of individual difference and that's probably going to be our main discussion point. Cam Nicholls (06:14.872) Yeah. Okay. So what, was there anything else that you found that was worth referencing? think the one that came to mind, which isn't so much about results, but it was more so relating to, was a paper done just recently and it wasn't, it wasn't a super comprehensive paper, but they looked at muscle activation and how your muscles respond differently on the indoor versus the outdoor, notably our calf, quadricep and shin. I'm not sure why they're measuring the shin muscle. You may have a better understanding why. I don't really think of my shin muscle and I think about cycling and the paper didn't look at glutes at all, which is probably a major oversight and probably a cost reason behind it. But it was interesting to note that a lot of people feel a different sensation when they're on the indoor and that paper is basically shining the light on, yeah, you are activating the muscles in a different way. Ben Treble (07:05.25) Yeah. think, can we finish on that paper? Cause I think it's a good way to wrap up the summary to some respect in the discussion. So when I did my little digging in the journals, I found a couple of papers and in summary, they all had a similar conclusion, which there's no measurable difference between indoors and outdoors when they looked at true threshold testing and mean maximal powers. Again, they're finding individual differences. So in the discussions, they talk about people who had more experience in indoor training, trended towards doing better on indoors than outdoors, which makes a lot of logical sense. And the people who, you know, spent 90 % of their time training outdoors, put them on indoor trainer and yeah, the RPEs went up higher and they couldn't do as, do as well as they do outdoors. So that makes sense. The papers are, if you are wondering, there's an unpublished paper coming out later this year at, science and cycling conference at the tour. So this is pre-publication paper, 2026 from Lee Inn, comparison of indoor outdoor writing ability. They looked at 18 males and 12 females. They're trained, but unprofessional. They found a moderate to high correlation between FTP results across indoor outdoor tests was 0.83. So not, I wouldn't call it a very strong correlation, but definitely not pointing the other direction enough to say there is a difference between the two. It's pushing you much more to a direction to say there's no difference. The other paper was from 23. It's a comparison of mean maximal powers. This one's probably slightly more nuanced because they looked at mean maximal powers across indoor outdoor testing. They also looked at recorded maximal powers from training data and competition data. This paper's from Sebastian Doock et al. They only looked at seven male amateurs. So again, very small sample size. Notably, the only power durations they ever really found measurable differences was a five and 15 second. So sprint power, very neuromuscular. No real measurable difference in the five and 20 minute power durations across all four of those environments or contexts. So yeah, and no significant difference in mean maximal powers for the indoor and outdoor testing at all. The only differences they really found was in within the training data, they often found higher. Ben Treble (09:24.46) sorry, lower maximal powers. And it was the race data where they were doing some of their peak powers outdoors. Okay. So a lot of context to that one. The third paper I looked at was a 2019 paper. So a bit older than the others. They did an analysis of it's the variability in power outputs. So that's where we're coming to our last discussion. During indoor outdoor cycling time trials, 20 male cyclists, no measurable difference in 20 minute time trial power between indoor and outdoor. However, What they did find was there's a greater variability in the power across the two. So in simple terms, they're finding no measurable difference in the average power for the 20 minute time trial. But if you were to look at the normalized compared to the average, you're going to expect a higher normalized for outdoors. So a greater degree of fluctuation in the power versus indoors where it's more steady state. Cam Nicholls (10:14.082) This podcast episode is brought to you by Stannards, a proud sponsor of the RCA's Pro Velo cycling team, RCA Bikes Online. And they've been a big supporter of Aussie cycling over the years. They're a Melbourne headquartered business with offices right across Australia. And they've been around since 1946, helping businesses and high net worth individuals with accounting, tax and broader business strategy. And just for a bit of transparency, I've actually known one of the partners since 1994. is a schoolmate of mine, in fact, a very good mate of mine. So I've seen firsthand how the business operates and the type of people they are. What I like about Stanars is they're not just your typical tax time accountant. They've got a fully integrated set up, so business services, audit and a strategic advisory so they can support businesses and high net worth individuals right across the whole journey. They work across a heap of different industries too. So they've got construction, manufacturing, healthcare, technology, hospitality, the list goes on and they're very accustomed to dealing with real world challenges. They've grown to over 110 people in recent times now backed by Pemba Capital Partners and they're continuing to expand. So if you're looking for a proper long-term advisory partner, not just someone to help you log your tax return, Stanarts are definitely worth a look. We'll drop a link. to their business in the podcast description and let's get back to the episode. Yep. Okay. Makes sense. Ben Treble (11:42.446) Yeah, it makes a lot of sense. Cam Nicholls (11:44.302) I'm just a bit of a side note. I'm one of those rare crazy people that has actually done that one hour test. Really? Yeah. On the indoor and outside. And I did it within like a two week period. So I gave myself like a couple of weeks because I was pretty fatigued. Yeah. So this is just an interesting anecdote. So I did three, this is when I was in better form than I am now, 365 Watts for an hour. Outdoors, that's average power, it's not normalized power. And 300 and think it was 336 watts or 335 watts, somewhere around that. This is about 30 watt difference on the indoor going all out for an hour. Don't recommend it to people at home. It was the worst thing ever. My physiological stress though on the indoor was a heat. My heart rate was just going through the roof. I think I hit an all time best heart rate number. So just dropping that one in there as you're going through the research paper. Ben Treble (12:35.222) Yeah, I think, I mean, that's where the discussion is going to lead us, right? It's one thing for the research to say, here's what we see. It's another then kind of confirm or validate why is it different to what we see in practice? So currently, like from the research I've found and seen, I wouldn't expect within testing, like you should be able to do the similar power indoor outdoors. There's no difference. So then why in practice are we seeing reasonable differences? And a lot of the papers still talk about this, it's, it's again, it's environment and context, including bike setup or equipment setup. Even if you were just, for example, to go within outdoor cycling, you can change the environment and see significantly different, you know, test results. You could say, go do a one hour effort up climb and go do a one hour effort on the flat. If you go take a climber and say, go do one hour on a climb and then try to do one hour at the same power on a flat. you're probably going to see just as big variation in power output as you did with indoor outdoor. And I think that's where the discussion is going to go. So why do we see this difference? Because you do have a lot of context. How much training are you doing indoor versus outdoor? That's probably the first part. And then we're going to talk about setup. Have you got fans? Have you got air conditioning with your indoor trainer? Core body temperature slowly rising up on indoor training is probably one of the biggest key factors. as to why the RP starts to go up as you experience heart rate starts to go up, especially during maximal longer efforts. And of course the RP is going to go through the roof as a result, like your power is going to drop off. Cam Nicholls (14:07.214) Yep, that's what happened. Ben Treble (14:09.398) Yeah. I mean, what is your experience, Cam, like with some of your writers who say indoor feels harder? Cam Nicholls (14:14.87) It's probably like when I reflect, they're probably less focused on indoor training. Maybe they're just getting into it. A lot of our, you know, as you would know, a lot of people that come on board to the RCA don't necessarily, there were a lot of indoor training initially, but then they start embracing it because they recognise the benefits, particularly around doing structured training, being able to hit your targets and being efficient as well during the week. So I think a lot of them are inexperienced on the trainer and thus struggle with it a bit because they're not used to it. It's a different adaptation. But then conversely, you know, we've got some members and Thomas Martinez, the cycling tattooist on YouTube comes to mind who train with us for a bit. And he's actually stronger on the indoor trainer. His power numbers are better and he prefers the indoor, but he does most of his riding indoor. It does make a lot of sense. Ben Treble (14:59.678) That makes a lot of sense. This is back to that paper you briefly mentioned earlier. Why else would there be a difference indoors and outdoors? I think if you're a newer rider, of course, if you've never done indoors, again, one of the biggest differences, those Ergo trainers, especially if you turn Ergo on and for people listening, if you haven't done it, Ergo holds you to a certain power. So if you turn it on, it forces you to push that power. And not only do you have to push, let's just use 200 Watts as an example, it forces you no matter what your cadence is, you have to push 200 Watts evenly through the entire pedal stroke. And even if you get a very well trained cyclist and you say, do a steady state effort outdoors, if you look at the power production through the pedal stroke, it'll never be like force applied evenly through the full stroke. They might get it very good, but it's not going to be perfect. And then if you look at the indoor training, It forces you to hold it through the full pedal stroke. So what does this do as a result? Well, if you haven't done it very much, it's going to feel significantly harder because you've got to apply force evenly through the entire stroke constantly. There's no point at which you can just have that little back off at the top. Cam Nicholls (16:12.086) Yeah, or coast down the hill or like what most people do when they're outdoors. Ben Treble (16:15.31) Yeah. So suddenly this accumulates even a one hour zone two feels significantly harder than zone two outdoors. So this paper that you brought to me that started this conversation is pretty recent, 2025 or late 2025. I'll probably pronounce it wrong. Why Chi Tasi at all? Again, it's from Journal of Science and Cycling. Its focus was on not if there are differences in power necessarily, but it wanted to understand more about why is there a difference in the variability of power, which brings us back to that other paper I spoke about where they found no difference in power output. The difference they found was greater variability in power with outdoor riding. So these guys, went and did indoor outdoor testing. They've gone and essentially struck, you know, electrodes on different muscle groups to work out which groups are activating more or less at different points. And what they were finding is ultimately the quad and the calf had significantly higher activation during indoor cycling. So if you're pushing the same Watts, but you're your quads and your calves a lot more, that means you're using other muscle groups less. So you're essentially just going to work the quads, these big muscle groups more earlier and faster, which will lead to fatigue faster earlier and RPE higher. Makes a lot of sense. mean, they don't really, you know, they don't propose too much like why is that the case? They essentially just summarize with a needs more research, of course. Yes. Love our labs. Cam Nicholls (17:29.432) Yep, hiya. Ben Treble (17:41.986) I don't know what's your hypothesis. Cam Nicholls (17:43.842) I mean, I'm surprised it didn't do the glutes, but it made a lot of sense to me because it's the feedback we get from lot of amateurs that, just feels a bit more challenging on the indoor, feels harder. So yeah, I think there's a lot more to it, which we've sort of discussed during this chat. For example, know, cooling and high heart rates, but the activation side, which is what that paper is about was, yeah, just validating what I already assumed. Yeah. Ben Treble (18:08.718) And I think it's too easy on the indoor trainer. lot of people, again, this is a hypothesis. I don't have any data to support this, but N equals one. And you know, my glutes turn off. I already have glutes and I struggle to activate them on the bike and that's outdoors. And as soon as you stand up, even a couple times in a ride, you're going to activate your glutes a little bit and it just turns them on. And in indoor training, you have a tendency to sit down a lot more and you can put a lot more weights and hold your body up just using your arms and by sitting a lot easier. And you just rely on the quads and as a result, also the calves to pull through that stroke. Cause you're trying to get this, you've got this applied torque through the full stroke. So you're going to be turning off your glutes. And also I think your quads. So I think your upper body, which does take, you can be able to push some force through moving the bike sideways, which we all know. So it's just contextual. think you can't do that, which means you have to rely on these major muscle groups more. They fatigue earlier and therefore ergo, feels harder. The guys who train indoors more. They're just used to this. Yep. So they can still push the same power. It's the same quad muscle. The muscle hasn't changed. is power. Power's not changing in the same power meter. So yeah, I mean, if you get the air conditioning and the airflow with the fans right, and the context in the environment is similar, I don't see why you can't push the same output, but it's just like practicing. You give someone a bike with a different bike position where they activate the muscles slightly differently, it's going to feel totally wacko. Cam Nicholls (19:32.994) Yeah. So what would you say the key takeaway is? Because I would have thought a lot of people that are listening to this, particularly the end of the podcast, may struggle a little bit more indoors. So they've just heard all the research and they've heard some anecdotes. If they're struggling a little bit, what's the key take? And I'll start with takeaway one, make sure you're using the same power. Yeah. Ben Treble (19:52.672) That's one. Two, if you're new to indoor training, don't be afraid to down-regulate the power a couple percent. It's easy to just, I would pop the percent down a little bit if you need to. That's one until you get used to it. Now it does get easier the more you do it, but you have to do more of it to get used to it. And the third tip, which I would do actually is if you want to make this a bit easier, it'd be an interesting experiment is before you do your warmup on the bike with the indoor trainer, get an exercise band and a yoga mat next to your trainer. and spend even just five minutes, 10 minutes doing some glute activation exercises with the bands to turn your glutes and do a little bit of core work to turn your core on before you get on the indoor trainer. Okay. Cam Nicholls (20:36.466) interesting. might try that myself. I haven't heard of it. Haven't heard that one. And the fourth one I'll say is, you know, I think a lot of people get on Zwift or, you know, these indoor platforms and go, oh, that looks like a fun ride. Cause it's like they're seeing all these bars popping up and down, but it's probably a brutal ride. So, you know, as you kind of said, ease into it, start progressively on the trainer. Don't do really difficult workouts upfront. You know, pick something that looks a little bit easier and work from there. Yeah. Cool. Ben Treble (21:02.51) Definitely. Cam Nicholls (21:04.398) All right, thanks for time, Ben. Much appreciated. If you're out there listening and you're looking to integrate indoor into your training a little bit more strategically, make sure you check out the RCA's website, One-to-One Coaching. You can work with one of our coaches and get that down pat. That's at www.roadcyclingacademy.com. We'll catch everyone in the next podcast.
