Triathlon Off-Season Training: What to Do From November to March

The race season ends, the medals go in the drawer, and then comes the question nobody plans for: what are you actually supposed to do between November and March? Most age-group triathletes get the off-season wrong in one of two directions — they either stop entirely and surrender their fitness, or they keep hammering race-season intensity until they burn out in February. The off-season is neither a holiday nor a training block. It is its own phase with its own job: fix your weaknesses, build your engine, and arrive in spring hungry.

The three phases of a smart off-season

Phase 1: Real rest (2–4 weeks after your last race)

Take genuinely unstructured time. Swim because the water feels good, ride with no computer, hike, sleep. Two to four weeks of this costs you almost nothing — aerobic fitness built over years fades slowly — and repays you with the single thing no training plan can give you: wanting it again. Athletes who skip this phase are the ones quitting in March.

Phase 2: The strength and skills window (roughly November–January)

This is the season to do everything you cannot do in July:

• Strength training, 2–3× per week. This is the off-season priority, not an add-on. Squats, deadlifts or hip hinges, lunges, calf raises, core. Heavy-ish, low reps, full recovery. The watts and the injury resistance you buy here pay out all season.
• Swim technique overhaul. The off-season is the only time you can afford to get slower for six weeks while rebuilding your stroke. Drills, video analysis, shorter sets at better form — our front crawl drill guide is built for exactly this.
• Indoor bike quality. Winter is structured-trainer season: two quality sessions per week beat four junk-mile rides. Our guide to indoor cycling for triathletes and the Zwift vs Rouvy comparison cover the setup.
• Run frequency over run volume. More short easy runs, fewer long ones. Frequency builds durability; winter long runs mostly build injuries.

Phase 3: The base build (roughly February–March)

Now volume creeps back up, long rides and runs return, strength drops to maintenance, and you transition into your race-specific plan — ideally starting a structured program like our free 20-week 70.3 plan about five months before your A-race.

A sample off-season week (December)

Total: 7–8 hours. Roughly half of a peak race-season week — enough to build, light enough to leave you fresh and with a life.

The five off-season mistakes that ruin race seasons

1. Racing your trainer app all winter. Virtual races every weekend in December is race-season stress in disguise.
2. Skipping strength because “it is not swimming, biking or running”. It is the highest-return training a time-limited age grouper can do, and winter is its season.
3. Chasing summer weight in December. A couple of winter kilos are normal and hormone-friendly. Aggressive dieting plus training stress is how you get sick all winter.
4. No structure at all for four months. Unstructured does not mean absent — two or three anchored sessions per week preserve years of adaptation.
5. Starting your race plan in January for a September race. You will peak in June and limp to the start line. Count backwards from your A-race instead; our guide to build vs peak phases explains the timeline.

FAQ

How much fitness do I lose if I take a month off?

Measurably some, meaningfully little. VO2max dips within 2–4 weeks of full rest, but years-deep aerobic base returns within weeks of resuming. The motivation you regain is worth more than the watts you temporarily lose.

Should I do a winter running race?

A low-pressure 10K or half marathon in late winter is a great base-phase anchor — treat it as a hard workout, not an A-race taper event.

When should I start my 70.3 plan?

Count back 16–20 weeks from race day. For a June race, structured training starts late January — which is exactly why the off-season strength window matters now.