The triathlon off-season is where bike legs are built. Not during race-specific training, not in the final 8-week block before your A-race — in winter, when nobody's watching, when the sessions aren't glamorous, and when the consistent athletes separate themselves from the rest.
If the bike is your limiter — and for most age-group triathletes, it is — then the off-season is your opportunity to make a step change in cycling performance that carries through the entire race season.
Why Winter Cycling Matters for Triathlon
During race season, your cycling training is constrained. You're managing fatigue across three disciplines, fitting in brick sessions, and tapering for events. There's limited room to push cycling volume or intensity without compromising swim and run quality.
The off-season removes those constraints. You can temporarily reduce swim and run volume, increase bike focus, and build the aerobic engine that underpins everything else. This is the base training approach that pure cyclists have used for decades — and it works just as well for triathletes.
When Olav Bu came on the podcast, a core principle of the Norwegian training model was immediately clear: the best endurance athletes build enormous aerobic bases before layering race-specific intensity on top. He described how he works backwards from race day for Blummenfelt and Iden — defining the goal, quantifying the gap, and then structuring every training week around closing it. "I don't have a determination of what and how," he told us, "it comes more down to where do we think is the most to be improved compared when we look at the gap." For most age-groupers, that gap is on the bike, and winter is when you close it.
Josh Amberger, one of the best swimmers in professional triathlon, made a crucial point when he came on the show: "I'm not ashamed to take time off. Being 34 now, I'm looking at the last five years of my career potentially. What's going to really pay for me in the back end of my career is being able to really differentiate when we're in season and when we're offseason." If a professional triathlete takes genuine downtime, you definitely should too.
Phase 1: Recovery and Reset (Weeks 1-4)
After your final race of the season, take 2-4 weeks to decompress. This doesn't mean doing nothing — it means unstructured activity with no training plan, no power targets, and no guilt.
- Ride your bike when you feel like it, for as long as you feel like it
- Try different things: mountain biking, gravel riding, easy group rides
- Address any niggles or injuries — see a physio, get a bike fit check, sort out that knee pain you've been ignoring
- Sleep more. Eat well. Let your body actually recover
This phase is psychologically important too. Ben Hoffman told us on the podcast: "A happy athlete is a fast athlete. Peak performance only happens when everything in life is vibing — relationships, nutrition, rest, connected with family and friends. It really takes all of that." Triathlon training is relentless. You need a mental break before committing to another training cycle.
Dan Lorang reinforced this: "High performance sport is not healthy. We have to be clear on that. Amateur athletes should leave a much bigger reserve from that border." If Roglic's coach is saying this about amateurs, take the rest.
Phase 2: Aerobic Base Building (Weeks 5-12)
This is where the real work begins. The goal is to build your aerobic capacity through consistent Zone 2 training — the kind of riding that feels almost too easy but drives profound metabolic adaptations over weeks and months.
Professor Seiler's research, which he broke down in detail across two episodes with us, is unambiguous here. The 80/20 distribution — roughly 80% of training at low intensity, 20% at high intensity — produces the best outcomes across all endurance sports. He explained that for time-crunched athletes with limited hours, the key is prioritising one long ride per week plus distributing intensity strategically rather than riding hard every day in the grey zone.
He also gave us one of the most useful practical markers I've heard: "The whole profile drops down and shifts to the right — they can cruise at 0.7 millimolar lactate whereas the average person is at 1.8. That's real efficiency, and it often happens pretty fast once you're disciplined with green zone training."
Weekly structure:
- 3-4 cycling sessions per week
- 1 long ride: 2.5-4 hours, entirely Zone 2
- 2-3 shorter rides: 60-90 minutes, Zone 2 with optional short tempo blocks
- 1-2 swim sessions: maintenance only
- 1-2 run sessions: easy volume, no intensity
Volume targets: Aim for 8-12 hours of cycling per week during this phase. That's significantly more than you'd manage during race season, and it's the extra volume that drives adaptation.
The key discipline: keep Zone 2 genuinely easy. The temptation to push into tempo is enormous, especially on the turbo when you're bored. But the physiological adaptations — mitochondrial biogenesis, fat oxidation, capillary density — happen at low intensity. Riding harder doesn't accelerate these adaptations; it just adds unnecessary fatigue.
Lorang gave us a brilliant practical tip: let heart rate guide intensity over power, especially for endurance work. Heart rate reveals how your body is actually responding to load — fatigue, stress, illness — whereas power output can mask whether you're truly in the right zone.
Phase 3: FTP Development (Weeks 9-16)
As your aerobic base develops, layer in structured intensity to raise your FTP. This overlaps slightly with the base phase — you'll start introducing intervals around week 9 while maintaining high Zone 2 volume.
Effective interval sessions for triathlon cyclists:
Sweet spot intervals (88-93% FTP): 2x20 or 3x15 minutes. The bread and butter of FTP development. These sit just below threshold — hard enough to drive adaptation, manageable enough to recover from.
Threshold intervals (95-105% FTP): 4x8 or 3x12 minutes. Closer to your FTP ceiling, these push the top end of your sustainable power. Limit to once per week.
VO2max intervals (106-120% FTP): 5x4 minutes or 6x3 minutes. These raise your ceiling, which in turn makes your race power feel easier. Once per week maximum, and only when your base is solid.
Seiler's advice for structuring these is gold: establish frequency first, then duration, then — and only then — intensity. Most amateurs reverse the order and wonder why they're always tired. As he told us: "Success hinges on the floor — your first lactate threshold power output — not the ceiling. Consistency and staying healthy enough to complete 300-600+ workouts per year trumps any single breakthrough session."
The sweet spot training approach is particularly effective for triathletes because it provides a high training stimulus relative to recovery cost — critical when you're also maintaining swim and run fitness.
Strength Training: Your Secret Weapon
The off-season is the ideal time to incorporate strength training for cycling. Heavy lower-body work — squats, deadlifts, lunges, step-ups — builds the muscular endurance that sustains power output over 4-6 hours on the bike.
Off-season strength schedule:
- 2-3 sessions per week during Phase 1-2
- Reduce to 2 sessions in Phase 3
- Maintain with 1 session per week during race season
Focus on compound movements with progressive overload. You're not bodybuilding — you're building the structural strength to maintain power output when fatigue sets in during the final third of an Ironman bike leg.
Lorang specifically recommended prioritising coaching, bike fit, and nutrition consultation over expensive gear: "Three modest investments — a good coach for load management, a bike fit session, and 3-4 nutrition consultations — yield lifelong returns and cost far less than high-end equipment." Winter is the perfect time to make those investments.
Indoor Training: Making Winter Count
Indoor training is a triathlete's best friend in winter. The controlled environment means every minute counts — no traffic, no coasting, no junk miles. A 75-minute structured session on the turbo can deliver more training stimulus than a 2-hour outdoor ride with interruptions.
Use the indoor trainer for your structured sessions (intervals, sweet spot, threshold) and ride outdoors for your long Zone 2 rides when conditions allow. The combination gives you the best of both worlds: precise execution of quality sessions plus the mental health benefits of riding outside.
Lorang gave us a practical alternative for the deepest winter months: substitute cross-training for bike endurance. Running, cross-country skiing, or even walking can build your aerobic base if you match heart rate zones. It gives you flexibility, mental freshness, and injury prevention without sacrificing adaptation.
Bringing It Back Together
Around 12-16 weeks before your target race, start reintegrating full triathlon training. Increase swim and run volume gradually, reduce cycling volume slightly, and introduce race-specific sessions like brick workouts and course simulation rides.
The cycling fitness you've built in the off-season doesn't disappear when you reduce bike volume. It provides the foundation that makes race-specific training more effective. You're not starting from scratch — you're sharpening a blade that's already been forged.
Olav Bu treats these transitions like quarterly business assessments — regular checkpoints to see where resources are being wasted and where the best returns lie. Apply the same thinking to your transition from base phase to race prep. What improved? Where are the remaining gaps? What does the data tell you about where to focus next?
Key Takeaways
- The off-season is your best opportunity to make a step change in cycling performance
- Take 2-4 weeks of genuine recovery before starting structured training
- Build an aerobic base with 8-12 hours per week of Zone 2 cycling for 6-8 weeks
- Use our FTP Zone Calculator to set accurate training zones for each block
- Layer in FTP development with sweet spot and threshold intervals from week 9
- Incorporate 2-3 strength sessions per week — compound lifts for cycling-specific power
- Use indoor training for structured sessions and outdoor riding for long Zone 2
- Reintegrate full triathlon training 12-16 weeks before your target race
Frequently Asked Questions
How long should the triathlon cycling off-season be?
A proper off-season is typically 4-8 weeks of reduced or restructured training, followed by 8-12 weeks of base building before race-specific training begins. The total period from last race to structured race prep is usually 12-20 weeks. Use the early weeks for recovery and cross-training, then progressively increase cycling volume and introduce structured intensity.
Should triathletes do indoor cycling training in the off-season?
Indoor training is excellent for structured cycling work in the off-season. The controlled environment eliminates junk miles and lets you execute precise intervals. Use a smart trainer with a power meter for structured sessions like Zone 2 rides, sweet spot intervals, and FTP development work. Aim for 2-3 structured indoor sessions per week, supplemented by outdoor riding when conditions allow.
Can triathletes drop swimming in the off-season to focus on cycling?
Yes — temporarily. If cycling is your biggest limiter, reducing swim frequency to 1-2 maintenance sessions per week for 6-8 weeks while increasing bike volume is a valid strategy. You won't lose significant swim fitness in that timeframe, and the concentrated cycling block can produce meaningful FTP gains. Just ensure you return to full swim training at least 12 weeks before your target race.
