Winter Base Training for Cycling: Build Your Engine from November to February

Winter base training for cycling means taking a short break after your season, then spending November through February riding mostly easy in Zone 2, which is 56 to 75% of your FTP. Add one short, hard session a week and two strength sessions. What builds the base is not one epic ride but showing up week after week, so your Fitness climbs slowly and steadily into spring.

I live on the outskirts of Berlin, where winter is long, gray and dark by late afternoon. I also rode the Ötztaler Radmarathon in 2021 and 2022, an Alpine gran fondo with four passes and roughly 5,500 m (about 18,000 ft) of climbing. The biggest difference between my two finishes was how much I had left on the last climb. That kind of durability is exactly what a winter base is for, and you can't cram it into the three weeks before an event.

Step 1: Take a real break (it won't wreck you)

A lot of riders skip the break because they're afraid of losing fitness. Let's look at what actually happens.

WattRun, like many training apps, tracks three numbers. Fitness is a rolling average of your training load over roughly six weeks (a 42 day time constant). Fatigue is the same thing over about a week (7 days). Form is Fitness minus Fatigue. The full explanation is in Fitness, Fatigue, Form Explained.

Here's a worked example using that model. You end your season at Fitness 50 and Fatigue 55. After seven days completely off, Fitness sits around 42 and Fatigue around 19, so your Form jumps to about +23. After fourteen days it's roughly 36 and 6, with Form near +29. Fitness drifts down, but Fatigue drops much faster. You come back fresh, not from zero.

The physiology tells a similar story. In their review on detraining, Mujika and Padilla found that highly trained athletes lost between 4 and 14% of their maximal oxygen uptake in under four weeks without enough training, and blood volume dropped by 5 to 12%. That is real. But part two of the same review shows that reduced training keeps most adaptations: volume can be cut by 60 to 90% as long as intensity stays and you don't train much less often.

How long should the break be?

My recommendation for amateur riders: one to two weeks without a plan. Stay active, go for walks or hikes, spin to the coffee shop, just no structure and no numbers. I wouldn't go longer than three or four weeks completely off the bike, because the first rides back start to feel like starting over.

Step 2: Ride mostly in Zone 2

In Andrew Coggan's power levels, Zone 2 (Endurance) is 56 to 75% of FTP and 69 to 83% of your threshold heart rate. At an FTP of 200 W that's 112 to 150 W. Coggan describes it as an "all day" pace where you can talk the whole time.

The hard part is staying there. On climbs, keep your power down even if that means a lower gear and a slower pace. In a group, let the wheel go when the pace creeps up. If you don't know your numbers yet, the FTP calculator gives you your zones, and Zone 2 Training Cycling explains why this intensity works.

Step 3: Keep a little intensity

Stephen Seiler's 2010 review describes how successful endurance athletes distribute their training: about 80% of sessions are low intensity, below roughly 2 mmol/L of blood lactate, and about 20% are hard, such as intervals near maximal oxygen uptake. Very little happens in between.

It's not just an elite thing. In a crossover study with twelve trained cyclists, Neal and colleagues (2013) found that six weeks of polarized training led to bigger gains than a threshold model, even though the polarized block had fewer hours (6.4 vs. 7.5 per week).

For your winter, one hard session a week is plenty, for example 3 to 5 × 5 minutes in Zone 5 (106 to 120% of FTP) with 5 minutes easy between. On a 4 hour week, every other week is fine. More on the 80/20 split in Polarized Training Cycling.

Step 4: Show up every week

A five hour ride followed by four days on the couch feels productive. Four normal rides every week are worth more. Your Fitness is an average over weeks, so every ride adds a little and no single day saves a month.

Six hours every week beats alternating ten and two. Every third or fourth week, cut your volume roughly in half so Fatigue stays in check and you actually want to get back on the bike.

Sample weeks for 4, 6 and 8 to 10 hours

Z2 is 56 to 75% of FTP, Z1 is below 55%, Z5 is 106 to 120%. Strength means 30 to 45 minutes in the gym or at home.

Move days around to fit your life. Two rules: don't put heavy strength work the day before your intervals, and when you have more time, make the easy rides longer instead of adding intervals.

Indoor trainer or riding outside in the cold?

Use both. The trainer is the best Zone 2 tool you own: no wind, no stop signs, no hills pushing you out of your zone. On weeknights when it's dark at 5 pm, it's often the only realistic option. Put a big fan in front of you and line up something to listen to for longer sessions.

Save the long ride for outside when the weather allows. A few cold weather basics:

• Layer up: a base layer, an insulating layer and a windproof shell. Carry one layer you can take off.
• Hands, feet, head: winter gloves, shoe covers and a thin cap under your helmet make the biggest difference.
• Respect wind chill: on a bike you create your own wind, so it feels much colder than the thermometer says. The ACSM position stand on cold weather exercise uses a wind chill below minus 18 °F (minus 27 °C) as the point where frostbite risk rises sharply.
• Watch for ice: bridges and shaded roads freeze first. Run lights front and rear, even in daylight.
• Drink warm: an insulated bottle with tea beats a half frozen bottle of water after two hours.

Add strength training

Winter is the best time to lift because you don't need fresh legs for races. In their review, Rønnestad and Mujika found the strongest evidence for heavy strength training in cyclists, including better cycling economy. The WHO recommends that adults do muscle strengthening for all major muscle groups on at least two days a week anyway.

Keep it simple: squats, Romanian deadlifts, Bulgarian split squats, step ups, plus core work like planks. Start light with clean technique, then build toward fewer, heavier reps. Stop if your knees or lower back hurt.

How to tell your base is working

• A slow, steady rise in Fitness. No spikes, no crashes. Play with different weekly volumes in the Fitness simulator to see how the curve responds.
• More power at the same heart rate. Once a month, repeat the same test ride, for example 45 minutes on the trainer at a fixed Zone 2 wattage. If your heart rate drops at the same power, your base is growing. Joe Friel calls the related metric decoupling: if heart rate rises less than 5% relative to power from the first half to the second half of a steady ride, your aerobic endurance at that intensity is well developed.
• eFTP: WattRun estimates your FTP from the power data of your last 42 days. If it barely moves during the base block, don't worry. Without hard efforts there simply isn't much data to estimate from.

Common winter base mistakes

Going hard too often

The group ride that turns into a race. The virtual race on Tuesday night. The extra intervals "just because." Each one costs recovery your easy rides need. One hard session a week is enough.

Letting the break run too long

Two weeks off quietly becomes six, and January feels like a restart. Pick your start date before the break begins.

Chasing numbers

An FTP test every two weeks, a segment attempt on every ride, a mileage challenge in December. Base fitness shows up over months. If you need proof every week, you'll end up riding too hard.

How WattRun helps

If you'd rather not plan all of this yourself: WattRun builds your plan around the days you actually have time and adjusts it to your current Form. A quick daily check-in on sleep, legs and mood feeds into the session it suggests for that day. You can see Fitness, Fatigue and Form as a curve, so you know whether your winter is working. You can try it for free with the button below.

Sources

1. Mujika I, Padilla S (2000): Detraining: Loss of Training-Induced Physiological and Performance Adaptations. Part I: Short Term Insufficient Training Stimulus. Sports Med 30(2):79‑87. doi.org/10.2165/00007256-200030020-00002
2. Mujika I, Padilla S (2000): Detraining, Part II: Long Term Insufficient Training Stimulus. Sports Med 30(3):145‑154. doi.org/10.2165/00007256-200030030-00001
3. Coggan A: Power Training Levels, TrainingPeaks.
4. Seiler S (2010): What is best practice for training intensity and duration distribution in endurance athletes? Int J Sports Physiol Perform 5(3):276‑291. doi.org/10.1123/ijspp.5.3.276
5. Neal CM et al. (2013): Six weeks of a polarized training-intensity distribution leads to greater physiological and performance adaptations than a threshold model in trained cyclists. J Appl Physiol 114(4):461‑471. doi.org/10.1152/japplphysiol.00652.2012
6. Rønnestad BR, Mujika I (2014): Optimizing strength training for running and cycling endurance performance: A review. Scand J Med Sci Sports 24(4):603‑612. doi.org/10.1111/sms.12104
7. WHO (2020): Guidelines on physical activity and sedentary behaviour.
8. Castellani JW et al. (2006): ACSM Position Stand: Prevention of cold injuries during exercise. Med Sci Sports Exerc 38(11):2012‑2029. doi.org/10.1249/01.mss.0000241641.75101.64
9. Friel J: Aerobic Endurance and Decoupling, TrainingPeaks.