Should Cyclists Use Different Power Zones for Indoor vs Outdoor Training? (#294)

OVERVIEW
Cyclists almost always report a discrepancy between the power output and/or perceived exertion between indoor and outdoor cycling. Typically, this means struggling to achieve the same power output indoors than can be achieved outdoors for common workouts like FTP intervals or VO2 max efforts. Even easier Zone 2 rides can have higher RPE values (i.e., feel harder) indoors compared to outdoors. In Episode 294 of "The Time-Crunched Cyclist Podcast", Coach Adam Pulford reveals why indoor cycling feels harder, how you can narrow the gap between indoor and outdoor performance, and whether you should use different power training zones indoors vs outdoors.

TOPICS COVERED

• Why indoor cycling feels harder than outdoor riding
• Which types of cycling workouts are affected more by moving indoors
• How to narrow the gap between indoor and outdoor performance
• When to make different indoor and outdoor power training zones

RESOURCES

•  Indoor vs Outdoor Power Explained
• Knowledge is Watt: https://www.instagram.com/knowledgeiswatt/
  - Indoor vs Outdoor Power post 
• Can a Mismatch Between Course Gradient and Resistance Affect Performance When Using ERG Mode in a Zwift Workout? 

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HOST
Adam Pulford has been a CTS Coach for nearly two decades and holds a B.S. in Exercise Physiology. He's participated in and coached hundreds of athletes for endurance events all around the world.

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Transcript

Welcome And Topic Setup

SPEAKER_00 0:06

From the team at CTS, this is the Time Crunch Cyclist Podcast, our show dedicated to answering your training questions and providing actionable advice to help you improve your performance, even if you're strapped for time. I'm your host, Coach Adam Pulford, and I'm one of the over 50 professional coaches who make up the team at CTS. In each episode, I draw on our team's collective knowledge, other coaches, and experts in the field to provide you with the practical ways to get the most out of your training and ultimately become the best cyclist that you can be. Now, on to our show. If you're one of those riders who has a hard time hitting their power numbers while training inside, or wonder why you can crush it on the outdoor races and group rides, but you can't do the same virtually, this show is for you. We're a few months into 2026, and it's a normal time period for athletes to be training hard in North America, but they may be doing the majority of their training inside due to crappy weather. Some of you have written in asking if you should change your training zones for indoor riding. And some of my athletes have even been asking if it's normal not to be able to hit the same numbers inside versus out. So I think it's time to do an episode about this. Let's get right to it. When it comes to max power production, most people produce higher numbers outside versus inside, and that's for a variety of reasons. Let me pull up a piece of research that I love, and I love it for various reasons, including it's coming from somebody I've had on the podcast before, Dr. Gabriel Legello, who is producing just very rich content when it comes to cycling, performance, and like best practices for training. He his angle is at a professional level. Um, however, a lot of this stuff, not everything, applies to amateur athletes and in time-crunched athletes, but research over and over. And I've linked to this as well as a couple other articles for further read reading about how indoor versus outdoor power can be different. Okay. So a couple things here is I just want to mention that uh his company is called Knowledge is What. He posted this screenshot on Instagram uh just a couple months ago, and I did email him and ask if I could uh use this on the podcast. So be sure to follow him on Instagram because that's where you can get some quick advice like this and infographics, and you can always do further reading in links in his bio and things like this. And then for his work, go over to Substack and I encourage you to subscribe. If you're a full-on endurance nerd or you're a self-coached athlete, this is a great resource for you to dive deeper into all things performance. Uh, really encourage everybody to follow his work and uh subscribe to what he's doing because I'm a big fan, and if you want more knowledge, especially going into uh rabbit holes and deep dives, this is it. The other thing that I like about his uh his work is you can do those deep dives, but the every topic is probably a five-minute read. So, again, for a time-crunched athlete, somebody short on time or or or uh you only have so much time to read, he's really hitting the mark on this. Okay, so let's talk about what's going on in this infographic. We have power on the y-axis, time on the x-axis. We have four different durations of power being tested here: one minute, three minute, five-minute, and fourteen-minute powers. Why is this? Well, we're we're really testing anything from uh functional reserve capacity or anaerobic capacity in the one minute. Then we've got some uh maximal aerobic power in the three to five minutes. I'd call this VO2 power personally, but you've got uh anaerobic contribution playing into aerobic power production in those two different uh uh timescales, and then you've got a 14-minute power, which is going to relate to uh critical power, uh maybe like a short FTP, but across the board, we're getting a smattering of power durations that is applicable to performance and applicable to really like power durations that are going to apply to indoor racing and training. And if you read up here, it's 14 male cyclists that are legit pros, so very good power and uh the world tour. Okay. And down here we're we're seeing that, and again, the the red is an indoor and the green is outdoor, and we see that across the board, mean max power outputs or the highest average power is being achieved outdoors. Okay, this is this is for various reasons. Now, on Instagram, there was some shade thrown at this one saying, Oh, those those power numbers look low for professional riders. And it's like, first of all, like you don't know the weights of these riders, they could be smaller riders, but these power numbers are actually pretty legit, okay? So without knowing uh all the details, don't throw shade. Another comment was about heat dissipation. Um, did they actually have a fan going and things like this? I'm quite certain. I will go back and verify, but I'm pretty sure when I read this research that they did control for uh uh heat dissipation issues and they cooled the athlete when doing that. For anybody listening, when you're inside and you're doing zone four and higher, I highly encourage you to do it in a in a cooler environment with a fan going uh if you want performance out of that session. Okay. So I'm gonna leave this up as we talk and discuss a few more elements around this, okay? Because when and I talked about this a couple weeks ago in a in a different podcast where the outdoor power production being different than the inside, there's a lot of reasons for that, more than just the heat dissipation, okay, for myself as well as some athletes is motivation. If you ride outside more often than inside, you're generally gonna be more motivated for that outdoor session. If you enjoy the outdoors, you are more motivated for that. A lot of complaints I get from my athletes coming inside is like it's so boring. Oh my gosh, this sucks. Oh, all the technology issues, right? Motivation comes down for some people. But if you have everything set up and you've been training inside a little bit more frequently, the motivation is not that big of an issue. So that can be very individual. What's not all that individual, or what applies to everybody, is the physics of outdoor riding versus indoor riding. I'm talking about how you produce your power, right? How you produce power to get speed up, and then you have inertia and momentum on your side as you are doing harder efforts at speed, and you're also able to manipulate or change your body movement. You can get up and out of the saddle and utilize some of your body weight and some of your upper body mass to produce the power. You move the bike much differently inside versus out. Even on the best uh like bikes that can move laterally, it still feels super weird and it's definitely not the same. Okay, so when it comes to out of the saddle riding, maximum efforts and outdoor power production, let's just say the physics are drastically different. Again, the resistant forces can be very different as well. Meaning, we I talked about erg mode in a couple episodes back. Even in the best erg mode that I've seen, which is TPU virtual, it's the perceived effort is still a notch up for me. And I'll get to a few more reasons on that here in a minute. But the erg mode is going to set a resistant force for you to overcome in order to produce that power. Okay. As opposed to when you're outside riding, you're producing the power initially, getting that speed and momentum and inertia up. And it just feels very different. Okay. You're resisting a force inside versus producing a force outside. Go back 10, 15 years to a lot of these like fluid trainers and things like this, that resistance force is like a 360 degree around. Okay. So you're just like always, always pushing. And it's and that's good from a training standpoint because if you do a bunch of riding on a like a fluid trainer, you're strong as a beast and could pedal for you know all time when you're outside. Okay. But the problem is uh the perceived effort goes a lot higher, and the power production can be lower when you come inside on things like this. Now, the uh magnetic and smart trainers have done a better job of making it more like a road reel feel, and that's a good thing, but it's still not the same. Okay. Finally, how you make your best power applies here too. If you stay seated uh the majority of the time outside and you come inside, generally speaking, the max power production uh will be close to indoor versus out. Okay. Additionally, if you ride the majority of time inside versus out and you're testing yourself on a max power production, the outside versus inside power production numbers are gonna be relatively the same or similar. Okay. But if you ride outside more, and if you uh are out of the saddle more often for your maximum uh power outputs, now there's gonna be a drastic change in this. So it's really like how you make your power versus what you're used to in your normal training aspects that are going to cause a spread of the max power inside versus out. Okay. Now, for a little bit more explanation and even some um some like deep dive into the physiology and physics of this, there's a great article from High North that I'll link to in our show notes. And I've talked about uh these uh this group, High North. I need to get them on the podcast still, but they they produce some really good articles. So I really encourage anyone who uh either disagrees with this information that I'm giving or you're more curious about it, uh, go read that article. It's it's a very good uh summary in a in a short amount of time. Now, some of this is trainable, okay? The more, like I said, the more you train inside, the better you can get at producing power, maximum power inside. However, it is well established in research and in the data that most people produce their better power outside versus inside. So, should you change your training zones? Great question. My answer is yeah, for sure. Especially if your perceived effort is super high when doing, say, a threshold workout. So you want to test this first. Let's just say, for example, your FTP is 300 watts, uh, just for um uh keeping math simple. And you want to test this, so you do a four by eight zone four workout. If RPE is more like an eight, nine, or ten out of ten, and you're you're trying to hit uh 300, 310, something like this, uh, which is slightly over that FTP, but zone four does cover uh slightly over like that. The RPE is just through the roof, and you can normally crush this workout outside and you're getting crushed inside. I would change training zones. I would move down by five to ten percent, meaning uh put the FTP at 285 and try a workout there or try the next interval there. What you want to do is make sure that the threshold work aligns with more like a seven out of 10, maybe an eight if you're doing a lot of threshold work and you're getting toward the end, but adjust down by five to 10%. If the RPE is still high or you can't finish the workout, go down to 15% below of what that outdoor FTP is. The main thing is align the perceived effort with the effort that it should be based on those outdoor rides. Start there for a couple weeks, and as you train more inside, that gap should uh narrow a little bit. However, max power, I'm gonna not say will always be, but usually will be lower inside. So don't get too worked up about it, don't shame yourself about it. Accept it and acknowledge it and then train. Because what's happening here, if you look at the heart rate when you're doing these efforts inside, heart rate may be a little bit higher for the given power. So you may hug the low end of power and the heart rate's up in that zone where it should. That's fine. You're getting the cardiovascular response, you're getting the ventilatory response that you should. You're just not getting what I call the biomechanical response or the total work being done inside. To kind of make up for that with all the pedal strokes that you get inside because you're never coasting, um, you're always kind of on. So, in the end, it's still going to be a very great training session. Now, finally, I will say this this may not apply to everyone. I actually do have an athlete who historically has produced better power inside versus out, but this is because he has ridden a lot inside and he needs to work on uh anaerobic ability. Okay, he's a he's a big aerobic uh powerhouse for sure. Now, we're starting to see some of those best powers come out outside on the road versus the trainer, and that's really fun to see. But he's also seen new peaks on the trainer because it's been so cold around here uh that he's doing a lot of trainer work inside. Okay. Now, uh indoor training is a great tool. So don't think that I am you know anti-indoor from a uh training standpoint. It is very effective, and I uh it's probably uh sometimes more effective for the longer stuff. Okay. Uh however, if you have the ability to utilize an indoor training setup, um uh do it because it creates less barriers to entry to ride due to weather, traffic, daylight, and other problems that outdoor riding has, like getting flats and mechanicals and when the weather changes and all this kind of stuff. Okay. My point is definitely use indoor training as an option if you have it. But if you don't, don't power shame yourself by thinking you should or do more like you can outside. It's perfectly normal not to. And it's both trainable as well as like real physics and science kind of going against you inside. So just adjust training zones at as needed, align rate of perceived effort as they should be with all the other training zones, and make sure to have a fan going with proper clothing to help you stay cool on the hard days. And maybe, maybe you just enjoy the sweat on the zone two days and get a little extra heat training out of the deal. So that's it. That's our show for today. I hope you liked it. If you want more or you want to take it to the next level, you know where to find us. Trainwrite.com. Thanks for joining us on the Time Crunch Cyclist Podcast. We hope you enjoy the show. If you want even more actionable training advice, head over to trainwright.com backslash newsletter and subscribe to our free weekly publication. Each week you'll get in depth training content that goes beyond what we cover here on the podcast that'll help you take your training to the next level. That's all for now. Until next time, train hard, train smart, train right.