Winter Cycling Training, What It Is Actually For

James. Good to have you on the WattPlan Podcast. I'm James. Family, a proper job, building WattPlan, the odd podium in a good year, and a reading pile that's mostly physiology papers. The clocks have gone back, the evenings have shut down, and everyone tells you to do base miles and then leaves it there. So what is winter training actually for? Lyra's our AI research voice, and every study she mentions is linked in the show notes.

Lyra. The slow stuff. Winter is for the adaptations that take months, the aerobic engine and the habit of riding consistently. It's the one stretch of the year with room for them, and nothing is at stake if a single week goes badly.

James. Slow compared to what? I'd have said fitness is fitness.

Lyra. Some of it comes quickly. Your body learns to tolerate interval work within a few weeks, and top end power comes back within about a month of touching it again. Other things take much longer. More capillaries around the muscle fibres, more mitochondria, and the stubbornness that lets you hold a pace into the fourth hour. Those respond mostly to accumulated volume and consistency, which is why you can't cram them in March.

James. Mitochondria. The little power stations everyone mentions on the turbo forums.

Lyra. The parts of the muscle cell that burn fuel with oxygen, yes. We looked at two studies for this, and the first is about exactly them. It's a 2018 review in Sports Medicine by Cesare Granata and colleagues. Their reading of the evidence was that training volume may be the critical factor in how much mitochondrial content you build, while how hard you ride relative to your capacity matters more for how well those mitochondria work. [1]

James. So volume builds the factory, intensity improves the machines inside it.

Lyra. That's a nice way to put it, and the review found the two often move separately. Which is the case for a winter that's mostly steady riding with some intensity in it, rather than either one alone. What the review doesn't give you is a number of months. That part is reasoning from the physiology, not a figure from the paper.

James. And the second study?

Lyra. Stephen Seiler's 2010 paper in the International Journal of Sports Physiology and Performance. He looked across descriptive studies of national and international endurance competitors, training ten to thirteen times a week. They kept landing on the same pattern, about eight in ten sessions easy and about two in ten hard. And studies that piled more intervals onto people who were already well trained didn't show convincing long term gains. [2]

James. Ten to thirteen sessions a week. Most of us have got five hours, if the kids sleep. Surely five hours of easy riding does next to nothing?

Lyra. You're right to push on that, because it depends on your hours. Base is driven by volume, and volume is the thing most riders can't manufacture. At ten hours a week, a long, mostly easy block does what the textbooks promise. At five, a purely easy week is a small total stimulus, and most riders do better with some harder work in it. So I wouldn't tell you to ride everything easy.

James. So what does a winter week look like in WattPlan, then?

Lyra. Through the base phase, which is most of the winter if your event's in spring, it's mostly steady, with one or two sweet spot sessions depending on how many days and hours you give it, never on consecutive days. Roughly every fourth week is a recovery week with no hard sessions at all. And the plan is built from the days and minutes you actually have, so a short week comes out shaped differently from a long one.

James. What am I allowed to lose, though? Because my sprint goes to pieces by Christmas.

Lyra. Let it. Your peak power will fall if you stop doing peak power work, and that's fine, because it comes back faster than it left. What you want to keep is the habit and the aerobic base underneath it. A rider who reaches March with a blunt top end and four months of consistent riding behind them is in far better shape than one who spent the winter sharpening something they won't use until June.

James. And if you're new to this, how do you even tell whether it's working? A steady ride in December doesn't feel like anything.

Lyra. That's the honest problem with winter. Don't judge it ride by ride. Watch Fitness, the slow moving line built from your Load over about six weeks. Winter's job is to raise that line gently and keep it raised. A spike in January followed by three flat weeks is worse than a steady climb, and for someone new to structured training, four steady rides a week for four months will do more than three brilliant weeks and a lay-off.

James. What about people who train with power? I'm always tempted to test every month to see if anything's moved.

Lyra. If you train with power, get your FTP right early, so the winter's work is aimed at the right numbers, then leave it alone for six to eight weeks. Testing monthly turns a training block into a series of exams. WattPlan also estimates FTP from your best efforts and asks before it changes anything, so you don't need a test to notice progress.

James. And anyone racing next season, chasing a result in May or June?

Lyra. If you race, put a date in the diary now, an actual event rather than an intention to be fitter. Once the plan has that date, it works backwards from it through base, build, peak and taper, and knows when to stop adding Load and start sharpening. If your event's in May, you've got about thirty weeks, which is exactly why winter should feel unhurried.

James. Unhurried. I like that. But winter doesn't fail because people pick the wrong zones, does it? It fails because it's dark and wet and I'd rather be on the sofa.

Lyra. I agree with you completely. It fails for reasons that have nothing to do with physiology. It's dark, it's cold, the turbo is dull, and nothing is coming up soon enough to feel urgent. The riders who get through it have usually removed the decisions rather than found more discipline. The bike's already on the trainer, the session's already chosen. Every decision left for half past six on a wet Tuesday is a chance not to ride.

James. Which is a decent argument for having a plan, to be fair.

Lyra. It is. A plan earns its keep in winter because it has made those decisions before you're tired and cold. And while nothing's at stake, winter's also the time to fix the thing you've been ignoring. A position niggle, a strength imbalance, a fuelling habit. In season there's always a reason to leave it.

James. Where does the evidence run out on all this?

Lyra. Quickly, for a rider like you. Seiler was describing people training ten to thirteen times a week, and Granata's review is about mitochondria, not race results. Neither tested a winter built around a job and a family, and nobody can tell you how many months a five hour rider needs. We're reasoning from the pattern, not from a trial built for you.

James. So if someone wants to start this week, where do they begin?

Lyra. Two things. First, go to You, then Schedule, and set the days and minutes you'll really ride in December, not the ones you'd like to ride. Then, if you have an event next year, use Rebuild plan on the Plan page and give it the date. And fix one ignored thing while nothing's at stake.

James. So, honest hours, a real date, mostly steady with a bit of sweet spot, and stop worrying about my sprint until spring.

Lyra. And show up. A dull, steady December ride you actually did is worth more than the perfect session you skipped because it was raining.

Lyra. The full article and every study we mentioned are on the WattPlan blog, linked in the show notes. And if you've enjoyed this, follow the WattPlan Podcast wherever you're listening, so you don't miss the next one.

James. And if you want a plan built around the time you've actually got, get WattPlan on the App Store or Google Play. 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.