Zone 2 Training for Cyclists, What It Is and How to Do It

James. Hello, and welcome to the WattPlan Podcast. I'm James. Between family, work, the odd podium and building WattPlan, I read far more sports science than is healthy. And every single winter I promise myself proper Zone 2, then ride everything at the same sort of medium effort. So, simple question this week. Is Zone 2 actually worth the hours? With me is Lyra, our AI research voice. She's read the studies so you don't have to, and every one is linked in the show notes.

Lyra. Ha, I love this one. Short answer, yes, for almost every rider. Easy riding is how you pile up hours of aerobic training without paying for them in fatigue. The catch is that most people who think they ride Zone 2 are riding Zone 3, which is exactly the medium you just described.

James. Oh, guilty. Totally guilty. Okay, pin it down for me. What actually is Zone 2, in numbers?

Lyra. On power, it's roughly 56 to 75 percent of your FTP. FTP being the power you could hold for about an hour, flat out. So for a rider with an FTP of 250 watts, Zone 2 is about 140 to 188 watts. On feel, it's conversation pace. You can talk in full sentences, paragraphs even, and you finish the ride feeling you could have done more.

James. See, that's the bit that drives me mad. It feels way too easy to be doing anything at all.

Lyra. Right, and that's the whole point, and it's exactly why it's so hard to do. The adaptations are real, though. More mitochondria in the muscle, more capillaries around the fibres, a heart that pushes more blood per beat, and better use of fat as fuel at moderate intensities. None of that shows up during the ride. It shows up weeks later as more speed at every effort.

James. Hang on, hang on. But I've read that intervals give you the same adaptations, just faster. Surely if I've only got an hour, the hard stuff wins?

Lyra. You're not wrong, and the evidence backs you more than the Zone 2 fans like to admit. We looked at three studies for this episode. The first is a 2016 review in The Journal of Physiology by MacInnis and Gibala. It found that interval training produces the classic endurance adaptations too, and for the same amount of work, hard intervals tend to raise VO2max more than steady riding. VO2max being the most oxygen you can use in a minute. Intensity is a strong signal, minute for minute. [4]

James. So why aren't we all just smashing intervals every day?

Lyra. Because the bill is different. A hard session takes days to absorb. An easy ride takes a night's sleep. If you could only ride three hours a week, more of it should be hard. Once you're riding six, eight, ten hours, you can't make all of those hours hard and still recover, so the extra hours have to be easy, or they make you tired rather than fitter.

James. Oh, that's brilliant. So the easy riding isn't instead of the hard stuff. It's what lets you do more of everything.

Lyra. Exactly that. Which brings us to how the best endurance competitors actually train. The second study is Stephen Seiler's 2010 paper in the International Journal of Sports Physiology and Performance. He looked across descriptive studies of national and international level endurance competitors, not just cyclists, training ten to thirteen times a week, and they kept landing on the same pattern. About eight in ten sessions at low intensity, about two in ten hard. [1]

James. And if they pile more intensity on top of that, do they get even better?

Lyra. In his review, no. Studies that made already well trained competitors do more high intensity work didn't show convincing long term gains. So the elite pattern isn't an accident. It's what's left when people train a lot for years and find out what they can sustain.

James. Okay, but I'm not elite, and nor are most of the people listening. And I've heard the eighty twenty thing argued to death online. Polarised, pyramidal, whatever. Does it really matter which one I pick?

Lyra. This is where the newest evidence helps. The third study is a 2025 network meta-analysis in Sports Medicine by Rosenblat and colleagues, with Seiler as a co-author. It went back to the raw data from 13 studies covering 348 endurance athletes, and compared polarised training, lots of easy and some very hard with little in between, against pyramidal, where there's a bit more middle. For VO2max and for time trial performance, it found no real difference between the two overall. [2]

James. Wait, no difference at all?

Lyra. Overall, no. There was one interesting split. In the more competitive riders, VO2max tended to improve more with polarised training. In the recreational riders, pyramidal did slightly better. The authors read that as performance level changing the response. What both approaches share, and what the post leans on, is that the easy riding stays genuinely easy.

James. Really? So all that arguing online is about the little slice in the middle, and everyone actually agrees on the big slice at the bottom.

Lyra. Pretty much, yes. And I'd add the limits, because they matter. Those studies are mostly men, mostly over a few weeks to a few months, and none of them can tell you exactly how many hours of Zone 2 a rider with a job and a family needs. Nobody has tested that properly yet. So we're reasoning from the pattern, not from a trial that was built for you.

James. Right, let's do the reasoning then. Say I've got six to ten hours a week. What does that actually look like?

Lyra. On six to ten hours over four or more days, this is how WattPlan lays out a normal week. Two harder sessions, usually an hour to ninety minutes, sweet spot early in the plan with threshold and VO2max mixed in later, then one long ride, and everything else easy. So most of the week is still Zone 2, and the long ride carries most of it. Two to four hours, steady, on a flat or rolling route if you can find one. Later in a plan, some riders' long rides pick up a few tempo blocks.

James. And the harder sessions, why two of them rather than one big day?

Lyra. Because hard days need easy days around them, and two spread out recover better than one huge one. Unless you're new to it, WattPlan gives you two in a normal week once you ride four or more days and at least four hours. The mistake is turning the easy days into medium days because they feel like a waste. That's how you end up too tired to make the intervals count and not rested enough to build anything.

James. Love it. Let's split it out by who's listening. If you're new to this, where do you start?

Lyra. If you're new to structured training, ride easy and ride often, with one ride a week that has some sweet spot in it. That's how WattPlan starts a new rider, never more than one harder ride a week, whatever their hours. Use the conversation test on everything else. If you can only manage short sentences, ease off. When in doubt, go easier, and you'll recover faster than you expect.

James. And if you train with power or heart rate?

Lyra. Then hold the ceiling. Set your Zone 2 range from a current FTP and stay under the top of it, especially on climbs and when someone rides past you. On heart rate, watch for drift. If your heart rate keeps climbing through a steady ride at the same power, you're either going too hard, too hot, or under fuelled. And if you train indoors a lot, test your FTP indoors too, because most riders hold a bit less power on the turbo, mainly because of heat.

James. And if you race, or you're chasing a time at a big event next year?

Lyra. If you race, Zone 2 is still most of your week, but as the event gets closer, roughly eight to twelve weeks out, more of the hard work becomes specific. Sweet spot, threshold, VO2max intervals, whatever the event demands. The hard sessions get more targeted, not more frequent. That 2025 analysis did hint that competitive riders respond a little better to a polarised split, but it's a small effect, and WattPlan doesn't make the mix more polarised for faster riders, so sweet spot stays in your plan too.

James. Okay, last thing, and this is the big one for me. How do I actually stop myself riding everything at medium?

Lyra. Ha, the eternal question. A few things help. Ride the long ride alone, or with someone who agrees on the pace before you start. Pick flat routes, or accept that the climbs will drift into Zone 3 and soft pedal the descents rather than chase. Indoors, use a strong fan and something to watch. And give it time. You won't feel faster during Zone 2 rides. The gains arrive in recovery, over weeks and months.

James. Which is the hardest part. There's no buzz of having done something.

Lyra. That's why it works. You can ride Zone 2 on consecutive days without digging into your recovery, so you can do more of it, and that total volume is itself a big part of what drives the change.

James. Brilliant. So what's the homework this week?

Lyra. Three things. One, work out your Zone 2 range from a recent FTP, and write the top number down. Two, do one long ride where you never go above it, even on hills. Three, look back at last week and find any easy ride that drifted into medium. Next time, ride it properly easy.

James. Okay, in my words. Find my ceiling, respect it for one long ride, and stop letting easy days drift into medium. Easy days easy, hard days hard. I can do that.

Lyra. That's it, you've got it. And if you only remember one line, the easy riding has to stay genuinely easy. Everything else in the debate is the small print.

Lyra. The full article and every study we mentioned are on the WattPlan blog, linked in the show notes.

James. And if you want a plan that's built around the time you've actually got, that's what WattPlan does. Thanks for listening.

Voices produced with ElevenLabs. James's voice is a clone of his own, Lyra is an AI voice, and James reviews every episode.