What To Do in Winter – Off‑Season Triathlon Training Principles

Winter is not a five-month hiatus nor a time for aimless “base miles.” Instead, think of the off-season (generally, November–February) as a strategic reset and rebuild period. This is when you address your weaknesses, build resilience, and sharpen skills away from the pressures of frequent racing. In short, winter is for work, but of a smart and specific kind. It’s the phase to fix technical issues, improve your strength and movement quality, and lay the groundwork for a stronger season ahead. It’s also a time of mental recharge, to pursue other things, to make time for the things you didn’t have time for, and to maybe rekindle your love for sport. What winter is not for is obsessing over weekly volume or proving your fitness on Strava. Save the proving for race day.

Consider winter your “triathlon workshop.” It’s when you get under the hood of your swim, bike, and run to make improvements that aren’t feasible during race season. This might mean focussing on that shaky swim stroke or finally doing the strength training you neglected. The gains made (or missed) in winter will heavily influence your results come spring. It’s crunch time, but in a different sense. The focus is on controlled, purposeful training, not on accumulating stress, or obsessing over high-intensity metrics.

Finally, understand that the off-season is about consistency without pressure. You’re not peaking for imminent races, so you can train with a clear mind and focus on fundamentals. Embrace the relative quiet of winter: no finish lines or crowds, just you honing your craft. By spring, you want to be that “quiet athlete” who trained diligently behind the scenes and emerges far better for it. Consistent, sustainable work in winter makes you dangerous by summer.

First Principles: The Sense Endurance Winter Lens

To plan your winter training, start with core principles. At Sense Endurance Coaching, I cut through the noise with three priorities: strength, skill, and simplicity. In practise, this means focussing on what makes you a better triathlete (robust fitness and efficient technique) and stripping away what doesn’t (gimmicks, junk miles, and needless complexity).

• Build Strength: This is the season to develop the muscular and aerobic strength that will carry you through long races. I’m not talking about bodybuilding or chasing maximal lifts in the gym, I mean functional strength directly applied to swim, bike, and run. Think of it as discipline-specific strength. For example, use swim paddles to build a stronger pull, push big gears on the bike to strengthen your legs, and include hill runs or resistance work to toughen your run stride. A stronger athlete can train and race with less fatigue. Winter is when you create that strength reserve. While we never abandon this work in summer, you have the opportunity for even greater focus and gains thanks to the much lower weekly workload.

• Hone Skill: “Skill” encompasses technique and efficiency in all three sports. When time allows in winter, invest in form improvements, but always with transfer to racing in mind. This isn’t about achieving some aquablue ideal of perfect form in isolation; it’s about being able to hold good form under fatigue (more on that soon). Every session should have a focus: maybe it’s endless catch-up or 3/3/3 drills in the pool to fix your catch if that’s a limiter, or cadence exercises on the bike, or a run form cue to practice. But avoid “drill soup” (endlessly dabbling in every technique drill imaginable). Instead, pick a few high-impact skills to work on and practise them consistently. Remember that triathlon technique is about what’s effective when tired, not what’s pretty when fresh.

• Embrace Simplicity: Winter is full of contradictory training advice (“do only Zone 2!” vs “do high-intensity now!”). My approach is pragmatic: keep things simple, specific, and sensible. I don’t bog athletes down with 7 HR zones or gadgets if they don’t add value. Use tools (power meters, etc.) if they help, but don’t become a slave to them. Ultimately, learn to listen to your body. Focus on work that directly translates to race performance, and don’t do something in training just because a smartwatch or trending plan says so. Winter training doesn’t need elaborate periodisation graphs, it needs consistent work in the right areas.

Another first principle: No “All Zone 2, All the Time.” There’s a popular notion that off-season = just doing long slow distance (LSD) to build base. While building aerobic base is important, an exclusive diet of easy miles is a mistake for time-crunched athletes. In fact, many overuse injuries brew during those countless “easy” miles done with sloppy form, and logging huge volume can leave you fatigued without any speed to show for it. Doing high volume and poor quality is a double whammy. Instead, winter weeks should blend different efforts intelligently: easy sessions stay truly easy, and hard sessions have clear purpose, with not much in-between “grey zone” grinding.

In summary, my winter mantra doesn’t differ much from the summer one: focus on strength (become a more durable engine), practise skill under fatigue (so your technique holds together in hour 4, not just minute 4), and keep training simple but purposeful. Do this, and you’ll enter spring with not just “base” but a base plus: a stronger, faster, more efficient you.

Winter Swim Focus: Strength Over Drills

Indoor pool time is precious in winter, so use it wisely. Many triathletes spend cold months doing “technical” drill sessions aiming for a perfect stroke. The irony? Come race day (with a wetsuit, choppy water, and 1500m+ to swim), that painstaking technique often falls apart. Instead, adopt the Sense Endurance approach: build swim-specific strength and the ability to hold your stroke together under fatigue. In short, hold your stroke under load, no drill soup!

What does this mean in practise? It means making your swim sessions mimic the demands of a race swim. Anyone can swim with beautiful form for a 25m or when fresh; the real skill is maintaining effective form when you’re exhausted. This winter, trade some of the finesse drills for strength-focussed sets. Paddles and a pull buoy will become your best friends. These tools add resistance and isolate your upper body, forcing you to engage your lats, shoulders, and core, exactly what you need for open-water endurance. A typical Sense Endurance swim set might be something like 10×400m or even 40×100m at a steady, controlled pace with paddles and buoy for the majority of the session. No stopping every 50m to adjust your goggles or do sculling drills. You keep going, finding a rhythm and holding form as you tire. This develops the endurance to sustain a solid stroke for the entire swim leg.

Example Swim Workouts (Strength & Endurance):
- Steady Strength Endurance Set – Effort: M (Moderate): 40×100m freestyle with 10s rest, using pull buoy and paddles for all reps. Focus on keeping your pull effective (no slipping water) even in the last 5–10 reps. Maintain a moderate, steady effort you could sustain for a long time. This is about aerobic strength, not pure speed. The goal is no form deterioration by rep 20. If you start to thrash, take an extra 30s pause, refocus, and continue (quality over ego!). This kind of set trains you to swim strong and controlled while fatigued, exactly what you need in a triathlon.

- Tempo Endurance Pyramid – Effort: M to M (Moderate to Medium): 100-200-300-400-300-200-100m (pyramid up and down) with 20s rests. Use paddles and a pull buoy on the longer reps (300s, 400); no equipment on the shorter reps. Swim the short reps a bit faster (Medium effort, e.g. around threshold pace) and the long reps at a steady Moderate effort (Ironman pace). This teaches you to change gears and hold form. The equipment on longer reps helps build strength, while dropping paddles on shorter ones forces you to swim strongly with your “naked” technique.

(Both sessions use the E-M-M-M effort scale. “Moderate” here means a sustainable aerobic effort. You’re working but not out of breath, roughly Ironman effort. “Medium” is a step up: half-Ironman to threshold effort, hard but not a maximal sprint.)

These workouts illustrate the winter focus: enhancing swim endurance and strength. You’ll notice that I didn’t include 8 different drills with fins, snorkels, etc. It’s not that drills have zero value, but I avoid random “drill buffet” sessions. Instead, if I instruct drills or tools, it’s for a clear purpose, e.g. catch-up drill to fix an overly rushed stroke or the 3/3/3 drill to develop efficient strength. But the meat of your winter swim should be like your summer: actual swimming. This not only builds your engine but also the confidence that you can keep a strong stroke all the way to T1.

Winter Bike Focus: Big Gears, Big Gains (Turbo with Purpose)

If summer was all about long rides and maybe some outdoor café stops, winter flips the script. During the week, you’re likely indoors on the turbo trainer, which is fine, because the trainer can be a potent tool for targeted bike workouts. The key is to avoid the “just spin easy” trap or the opposite “Zwift race every session” trap. Instead, aim for purposeful bike sessions that develop muscular endurance, aerobic power, and efficient pedaling. The mantra: big-gear torque and aerobic power.

Triathletes aren’t pure cyclists. We have to run after biking, and most age-groupers don’t have the leg speed of pro cyclists. Training with a lower cadence (in a big gear) builds strength in your legs without huge strain on your heart/lungs, and it can leave your legs fresher for the run. It might sound counterintuitive if you’ve been told to “spin to win,” but consider that in triathlon you often ride at moderate cadences anyway (due to terrain or fatigue). Embracing big-gear work in training develops a muscular endurance that pays off on hilly courses and late-race fatigue. In winter, when rides are shorter, we can safely include such work to build a robust cycling base.

What does a typical winter bike week look like? Likely 2–3 trainer rides mid-week (30–60 minutes each), plus an outdoor ride on the weekend if weather allows. Each trainer ride should have a clear focus, not just mindless pedaling while watching Netflix. For example, one session might focus on cadence and pedal stroke, another on sustained aerobic effort, another on short hard intervals. It’s quality > quantity now.

Example Bike Workouts (Indoor Turbo):
- Big Gear Strength Intervals – Effort: M (Moderate)[17]: Warm up by 10 min of easy spinning. Then do 20×1 minutes at 55-60 rpm in a big gear (e.g. big chainring, moderate resistance on trainer) at a Moderate intensity (around your IM bike effort, not all-out). Take a 1 min easy spin between intervals. Focus on smooth force to the pedals. No grinding your knees, keep your core engaged. This workout builds cycling-specific leg strength and muscular endurance. You should feel a burn in your quads by the last minute of each interval, but be able to maintain the effort. It’s okay if heart rate stays relatively low; muscular strain is the goal. As a bonus, low-cadence work like this is gentle on your cardiovascular system but heavy on muscle recruitment. Perfect for off-season when you want strength without frying yourself. This set will stick around all season, but it is during winter you can truly focus on it because you will be hitting it well-rested.

- Aerobic Tempo Builder – Effort: M to M: After a warm-up, do 3×10 minutes at Tempo effort (upper Moderate to low Medium) with 2 min easy recoveries. Cadence natural. “Tempo” in this context means around 80–85% of your threshold. A solid aerobic effort you could hold for an hour in a race. This builds your aerobic power. If you have a smart trainer, avoid ERG mode rigidity. Learn to hold the power yourself within a small range (say, target 250W ±5W, if that’s your tempo). This improves pacing skill. Over a 6-week block, you might progress these intervals to 3×15 or increase the wattage slightly. The goal is to raise your comfortable sustainable output. (Effort note: This is a Medium effort if we consider it closer to half-IM pace; comfortably uncomfortable. Heart rate might be ~25 beats below max.)

- High-Low Cadence Mixer – Effort: E to M: Here’s a technique session: 5× (2 min high cadence @ 100+ rpm + 2 min low cadence @ 55 rpm) at an Easy effort, focussing on form, not power. Then 10 min steady riding at Moderate effort to finish. This drills pedalling skills (neuromuscular work) while also giving a touch of sustained effort. It’s a light session that keeps things interesting mid-week.

Winter Run Focus: Economy, Strength-Endurance & Safe Mileage

Running can be the trickiest discipline in winter. Dark evenings, icy paths, cold rain. Additionally, run fitness can be fragile: ramp up too fast and you’re injured; do too little and you lose your edge. The goal for winter running is two-fold: build run-specific strength & economy while staying injury-free. We want you to emerge in spring with durable legs and efficient form, not nursing a knee injury from a slippery January run.

Key areas to target: running economy (how efficiently you run), strength-endurance (your ability to maintain form and speed over distance), and robust biomechanics (“safe form” – running in a way that minimises injury risk). Here’s how to tackle each:

• Run Economy Work: Winter is an ideal time to subtly improve your run efficiency. You’re not doing all-out track sessions in snow, but you can do strides and short hill sprints to sharpen neuromuscular coordination. For example, at the end of an easy run, do 4–6×20-second strides on a flat or slight incline: these are relaxed, fast accelerations (not full sprints) focussing on good form. High cadence, light feet, upright posture. They teach your legs to turn over quickly and reinforce proper mechanics, without much fatigue. Another tool: uphill bursts. A few 15-second uphill sprints (with full recovery jogging down) build power and recruit muscle fibres that improve your economy and stride efficiency. These kinds of exercises improve your form “motor programming,” making your regular pace more economical. They’re also very low volume/high return – perfect for time-crunched athletes. And because they are so short, they’re generally safe on the joints (as long as you warm up well and the surface isn’t icy). Alternatively, hit the treadmill for a mix of 30 seconds hard, 30 seconds easy, alternating between 2%, 4%, and 0% inclines for a total of 45 minutes to an hour.

• Strength-Endurance Runs: This refers to runs that build your ability to hold pace and form when tired. Instead of just doing slow plods, include some steady efforts in your winter runs. We like moderate-pace long intervals or tempo runs that are hard enough to create fatigue, but not so hard that you need tons of recovery. For example, a staple could be 3×10 minutes at “steady state” pace (somewhere around your half-marathon or 70.3 race pace) with 2 min easy jog recoveries. This corresponds to a Medium effort (M), about 85–90% of your threshold, where you’re working but have things under control. Such a session forces you to maintain good form and pacing as your legs get heavy, mimicking the feeling of the back half of a race. Another is the progression run: e.g. 30-minute run where you gradually increase from Easy (E) to Moderate (M) to Medium (M) effort in 10-minute segments. This teaches you to finish strong and run negative splits.

• Safe Form & Injury Prevention: Winter miles won’t help if you can’t make the start line in spring. Prioritise staying healthy. Incorporate basic strength training for hips, glutes, and core (even 15 min twice a week of lunges, planks, single-leg exercises can do wonders to keep you robust). And choose safe running conditions: if it’s icy or pitch dark, there’s zero shame in hopping on the treadmill. In fact, treadmill running can be extremely useful, and I, ideally, have my athletes use it all throughout the year. You can do controlled tempo runs without worrying about slipping or elevation work at alternating inclines you can’t possibly do outside.

Example Run Workouts:
- Tempo Interval Run – Effort: M (Medium): Warm up 10 min easy. Then 3×8 minutes at Medium effort (around your half-marathon pace) with 2 min jog between. Cool down 5-10 min. Aim for a pace you could hold for perhaps 45–60 min in a race, in other words, comfortably hard. Focus on relaxed, efficient form (midfoot landing, steady cadence) especially in the last interval when you’re tired. This builds both your aerobic capacity and neuromuscular endurance. It’s a strength-endurance run that teaches you to run strong under fatigue. If outside, choose a flat predictable path or track to avoid interruptions.

(Effort note: Medium (M), you’re at ~85-90% of max effort; talking in full sentences is hard, but you’re not in a sprint.)

- Hill Repeats – Effort: M to Mad: Find a moderate hill (~4-6% grade). Warm up 10-15 min easy running. Then do 6×1 minute uphill at a strong effort – the first 45 sec at Medium effort, ramp to Mad effort in the last 15 sec (power to the top!). Walk or jog back down for full recovery (2-3 min) between reps. Focus on driving with your glutes and maintaining quick turnover. These hill repeats build leg strength and mimic the feeling of the final kick in a 5K, without the impact of flat sprints. They also reinforce knee lift and good form. Cool down with easy jogging. (Effort note: Hills naturally limit your pace, so “Mad” uphill is hard but still controlled by the climb; you won’t actually reach all-out sprint speed.)

In winter running, consistency trumps heroics. String together many weeks of solid (but not extreme) run training, and you’ll build a massive aerobic base and resilience. Avoid the mistake of doing your “long runs” too hard: save the truly hard efforts for the controlled workouts and let your easy runs be easy. Many athletes make the error of running all their “easy” runs at a medium effort because they feel they have to maximise training, in reality, that just accumulates fatigue without distinct benefit. Better to polarise: easy days easy, hard days hard. And don’t worry about building volume in winter: the goal is to improve running economy and get your body ready for another season of stress and adaptations. Don’t start too early with that.

By spring, thanks to your winter regimen, you should notice you’re running with a lighter, springier step (from strides and drills), you can handle maintaining a solid pace longer (from tempos/intervals), and your body is niggle-free and ready to increase mileage for race prep. You’ll have that coveted run durability that many only wish for. All earned through smart winter training.

Balancing Indoor and Outdoor Training

Winter training often means a lot of indoor workouts, but how much indoor vs outdoor is ideal? The answer: use both to your advantage. Each has unique benefits, and a blend will yield the best results (and keep you sane).

Indoor “Turbo” Training: Indoor sessions on the trainer or treadmill offer a controlled, consistent environment. You’re not at the mercy of weather, daylight, or traffic. This means you can exactly hit the intervals and intensities you plan. That precision accelerates progress. For example, doing bike VO2 max intervals indoors is often more effective: no downhills or stop signs to interrupt. Similarly, a threshold run on a treadmill lets you lock into pace without terrain fluctuations. If you’re time-crunched (and, honestly, we all are), that matters. You can train before work at 6am on the turbo, without spending 20 minutes layering up and checking your lights. And of course, safety and comfort: no icy roads on Zwift, no dark unlit park on the treadmill. Indoor training removes many winter “friction points,” enabling you to be consistent week in, week out. Consistency is the mother of improvement, so this is a big win.

However, indoor training has downsides if used exclusively. You miss out on real-world dynamics: wind, terrain, handling, and the simple joy of fresh air. This is where outdoor training plays its role.

Outdoor Sessions: Riding or running outside in winter (when feasible) develops aspects you can’t get indoors. Wind resistance, uneven surfaces, cornering, climbs and descents: these improve your bike handling and efficiency in variable conditions. Running on different terrain (trails, hills, even snow) builds ankle strength, balance and mental toughness. And importantly, outdoor training tunes your pacing intuition. On the trainer, you see your watts or pace; outdoors, you learn by feel that maybe you went out too hard if you’re struggling later. Facing headwinds or hills teaches you to adjust effort on the fly: a critical race skill. Also, nothing beats a sunny crisp winter run for a mood boost, or the camaraderie of a weekend group ride when weather permits. These keep motivation high through the dark months.

I encourage a mix: use indoor sessions for quality and precision (e.g. mid-week interval workouts), and sprinkle in outdoor sessions for endurance and skill (e.g. weekend longer easy ride, occasional outdoor run).

Plan with flexibility: If a snowstorm hits, ditch your “long ride” and do an interesting, varied ride on the trainer instead (maybe just following a course on Rouvey). If a rare mild sunny day comes, swap in an outdoor session for a mental lift. The key is you’re not rigid, the training effect can often be achieved in multiple ways. Just understand the trade-offs: for example, an outdoor ride might burn a bit more energy due to cold and engaging more muscles (core, etc.), whereas an indoor ride might be more time-efficient but also mentally tougher due to monotony. One interesting note: indoor cycling tends to use slightly fewer muscles (no balancing or bike rocking), focussing more on prime movers. This is great for targeted strength, but after a winter on the trainer, you’ll need a few outdoor rides to reawaken those stabilisers and handling skills. Don’t worry if your first spring outdoor rides feel hard, it’s a normal adaptation phase.

Common Winter Training Mistakes to Avoid

Even experienced triathletes can fall into off-season pitfalls that derail progress. Here are three big ones and how to avoid them:

Mistake 1: Hibernating in the Comfort Zone (All Training = “Easy” Paced)

The “zone 2 only” dogma has convinced some athletes that winter means doing all sessions at an ultra-conservative pace. Yes, a lot of aerobic, easy mileage is important now, but exclusivity is the issue. Plodding through every ride and run at a safe snail’s pace can leave you flat come spring. You’ve lost touch with speed and strength. Worse, accumulating high mileage with imperfect form can actually cause injuries or ingrained bad habits. As we discussed, winter is the time to work on strength and skills. An all-comfort diet misses that. Don’t be afraid to do hard 100s in the pool, hill reps on the run, or big-gear efforts on the bike. These won’t kill your base; they’ll enhance it by building fatigue resistance. Physically, you maintain muscle recruitment and range of intensities; mentally, you avoid boredom. Avoid the “all comfortable miles” trap. You’ll thank yourself in April when you still remember how to go hard. As a bonus, varying paces helps prevent overuse injuries that often stem from repetitive same-pace training.

Mistake 2: Turning Every Indoor Ride into a Race

On the flip side of the Zone2-only folks, we have the Zwift junkies. Smart trainers and online platforms are amazing tools, but they can also lead you into unstructured intensity hell if you’re not careful. The mistake is using winter to do every flashy Zwift race or random high-intensity group ride you see, with no overarching plan. Sure, it’s fun, you get a quick fitness bump, brag on forums, but by February you’re often burnt out or nursing a sore knee from all those max efforts.

Remember, training is not just about beating virtual people; it’s about structured progression. Zwift racing every week through winter is like racing year-round. You never truly rebuild or address weaknesses. Instead: use indoor tech wisely. Do structured workouts, and if you race, treat it as an occasional hard workout, not a measure of your self-worth. Perhaps limit races to once a month in winter, as a spicy test or to keep motivation. And avoid the trap of the “Hammerfest group ride” that leaves you shattered regularly. Consistency suffers if you’re always cooked or, conversely, if you only chase KOMs but neglect base work. In short, have a plan and stick to it. The point is: chaos is not a plan. A bit of chaos (like a fun Zwift race) sprinkled intentionally is fine, but some athletes do it out of boredom every other day, and they stagnate or overtrain. Follow the principle “Consistency Over Chaos” even indoors. Each workout should have a goal, even if that goal is just active recovery. Keep the majority of your sessions purposeful, and you’ll reap far more benefit than the rider who Zwift-races themselves into a plateau.

Embrace the Winter Grind (and Reap the Rewards)

By now, it should be clear that what you do in the dark, cold months fundamentally shapes your spring and summer race outcomes. Winter is where you forge the strength, skills, and resiliency that allow you to race at your best. It’s not about flashy breakthroughs or instant gratification. It’s about honing of technique, fitness, and biomechanis, done with intention and intelligence. It’s not about accumulating volume, stress, and adaptations so you start the season with your nervous system already tired and fried.

The Sense Endurance approach to winter cuts out the fluff and focusses on what works: consistent training that prioritises strength (both in muscles and mind), skill under fatigue, and simple effective workouts rather than any magic formula. It’s about having the confidence to train pragmatically, knowing that hammering every session isn’t necessary, but neither is hibernating on the couch. It’s about doing the right work, week after week, so that when you toe the start line in April or May, you have an unshakeable foundation beneath you.

Winter training can be challenging. There will be mornings you’d rather hit snooze, sessions in the pain cave where motivation wanes, maybe even setbacks like a niggle or a week of flu. But if you embrace the winter with a pro mindset, taking the opportunity to mentally and physically recharge, you’ll start the season fresh, eager, and with a body ready to start improving. Remember, racing well isn’t only about who trained the hardest; it’s about who trained smart and stayed consistent.

If you’re looking at all this and thinking, “This sounds great, but I could use some guidance tailoring it to me,” that’s where we can help directly. At Sense Endurance, I offer personalised coaching to take the guesswork out and apply these principles to your unique life and goals. My coaching plans are built on everything you just read: proven principles, personalised to you, no nonsense. With a coach in your corner, you get accountability and expert adjustments along the way (so winter training adapts to your reality, whether that’s a niggling Achilles or a sudden work trip). Check out my Coaching page to learn more and reach out. I’d be excited to guide you through a beast of an off-season and beyond.

Additionally, if you prefer a structured plan to follow on your own, I have ready-made Off-Season Training Plans tailored for various levels. These plans incorporate the workouts and principles discussed, from swim strength sets to great indoor run or bike sets, all laid out week by week. It’s like having the blueprint for winter success at your fingertips, refined from years of real-world coaching.