Free 12-Week Ironman 70.3 Training Plan
This 12-week template organizes swim, bike, run, brick, and recovery sessions for an athlete who already has a consistent base. Adapt it to your recent training, health, recovery, course, and available time; completing the schedule does not guarantee race readiness or a finish.
Use this as a template, not a prescription
The sessions assume an established endurance base and must be adjusted to current training, recovery, injury history, course and medical context. Do not make up missed work by doubling sessions. Stop for severe, sudden or worsening symptoms and seek appropriate professional advice.
Who is this plan for?
- First-time 70.3 athletes who already train consistently in all three disciplines
- Athletes who have completed a sprint or Olympic-distance triathlon and recovered well
- Athletes who can fit the listed sessions into a sustainable week without cramming
- Athletes prepared to adjust sessions for their health, experience, course, and recovery
Prerequisites before week 1
Begin only if these sessions are already familiar and recoverable. If they are not, spend more time building a base or ask a qualified coach to adapt the plan.
- Swim continuously in a pool with controlled breathing and safe technique
- Ride confidently outdoors, including braking, cornering, basic repairs, and traffic awareness
- Run consistently without a current injury or escalating pain
- Complete an easy ride of about 60 minutes and an easy run of about 40 minutes without unusual fatigue
- Obtain appropriate clinical clearance when symptoms, pregnancy, medication, or a health condition could affect endurance training
How to adapt the plan
- Treat the listed duration and intensity as a template. Reduce a session that is a large jump from your recent, recoverable workload.
- If you miss one workout, continue with the next suitable session; do not stack or cram missed training into later days.
- If you miss several sessions or a full week, repeat or simplify the week after recovery instead of jumping directly to the scheduled peak load.
- Separate hard sessions when recovery is poor, and replace open-water sessions with supervised pool work when conditions or competence make open water unsafe.
- Stop and seek appropriate medical advice for chest pain, fainting, unusual shortness of breath, or persistent or worsening pain.
Training overview
This plan is structured into distinct phases, each building on the last. Here's the breakdown:
Base Phase
Build aerobic endurance with low-intensity sessions. Establish consistency across all three disciplines.
Build Phase
Increase volume and introduce race-pace efforts. Add brick workouts and longer weekend sessions.
Peak Phase
Use the longest rehearsals only when earlier weeks have been absorbed well. Practise course-relevant skills in safe conditions.
Taper Phase
Reduce training stress while retaining familiar movement. Adjust the taper to fatigue, travel, and experience.
Weekly structure
- 3 swim sessions (technique + endurance)
- 3 bike sessions (1 long ride, 1 intervals, 1 easy spin)
- 3 run sessions (1 long run, 1 tempo, 1 easy recovery)
- 1 brick workout (bike → run transition practice)
- 1–2 rest or active recovery days
- Optional: 1 strength session (core + legs, 30 min)
Complete week-by-week training plan
Week 1
Base| Day | Workout | Details |
|---|---|---|
| Mon | Swim | 1,200m easy — 4×100m drill/swim, 4×50m kick |
| Tue | Bike | 45 min easy spin, Zone 1–2 |
| Wed | Run | 25 min easy jog, conversational pace |
| Thu | Swim | 1,400m — 200 warm-up, 6×100m with 20s rest, 200 cool-down |
| Fri | Rest / Strength | Optional 20 min core + glute activation |
| Sat | Bike | 60 min steady ride, Zone 2 |
| Sun | Run | 40 min easy, focus on form |
Week 2
Base| Day | Workout | Details |
|---|---|---|
| Mon | Swim | 1,400m — technique focus, catch-up drill, 6×100m |
| Tue | Bike | 50 min with 3×5 min at tempo effort |
| Wed | Run | 30 min easy with 4×30s strides |
| Thu | Swim | 1,600m — pull buoy set, 4×200m steady |
| Fri | Rest / Strength | 20 min core + hip stability |
| Sat | Brick: Bike → Run | 60 min bike + 15 min run off the bike |
| Sun | Run | 45 min easy long run |
Week 3
Base| Day | Workout | Details |
|---|---|---|
| Mon | Swim | 1,600m — 8×100m descending pace, 4×50m sprint |
| Tue | Bike | 55 min with 4×4 min at threshold |
| Wed | Run | 30 min easy + 4×1 min pick-ups |
| Thu | Swim | 1,800m — 3×300m at race pace, 200 cool-down |
| Fri | Rest / Strength | 25 min strength — squats, lunges, planks |
| Sat | Brick: Bike → Run | 70 min bike + 15 min run |
| Sun | Run | 50 min easy long run |
Week 4
Base (Recovery)| Day | Workout | Details |
|---|---|---|
| Mon | Swim | 1,200m easy technique work |
| Tue | Bike | 40 min easy spin, Zone 1 |
| Wed | Run | 20 min easy jog |
| Thu | Swim | 1,200m easy with fins, focus on body position |
| Fri | Rest | Full rest day |
| Sat | Bike | 50 min easy ride |
| Sun | Run | 35 min easy |
Week 5
Build| Day | Workout | Details |
|---|---|---|
| Mon | Swim | 1,800m — 6×150m at tempo, 4×50m fast |
| Tue | Bike intervals | 60 min with 4×5 min at threshold, 3 min recovery |
| Wed | Run tempo | 35 min with 15 min at half-marathon pace |
| Thu | Swim | 2,000m — continuous swim, race-pace effort |
| Fri | Rest / Strength | 30 min strength — single-leg work + core |
| Sat | Brick: Bike → Run | 80 min bike + 20 min run off the bike |
| Sun | Long run | 60 min at easy pace |
Week 6
Build| Day | Workout | Details |
|---|---|---|
| Mon | Swim | 2,000m — 4×200m at race pace, 4×100m drill |
| Tue | Bike intervals | 65 min with 5×5 min at threshold |
| Wed | Run | 35 min easy + 6×30s strides |
| Thu | Swim | 2,200m — 3×400m steady, 200 cool-down |
| Fri | Rest / Strength | 30 min strength |
| Sat | Brick: Bike → Run | 90 min bike + 20 min run, practice nutrition |
| Sun | Long run | 70 min easy, practice fueling |
Week 7
Build| Day | Workout | Details |
|---|---|---|
| Mon | Swim | 2,200m — 5×200m descending, 6×50m kick |
| Tue | Bike | 70 min with 3×8 min at race effort |
| Wed | Run tempo | 40 min with 20 min at tempo pace |
| Thu | Swim | 2,400m — open water simulation, sighting drills |
| Fri | Rest / Strength | 30 min injury prevention work |
| Sat | Brick: Bike → Run | 100 min bike + 25 min run |
| Sun | Long run | 75 min easy with fueling practice |
Week 8
Build (Recovery)| Day | Workout | Details |
|---|---|---|
| Mon | Swim | 1,500m easy technique |
| Tue | Bike | 45 min easy spin |
| Wed | Run | 25 min easy jog |
| Thu | Swim | 1,500m easy with pull buoy |
| Fri | Rest | Full rest |
| Sat | Bike | 55 min easy ride |
| Sun | Run | 40 min easy |
Week 9
Peak| Day | Workout | Details |
|---|---|---|
| Mon | Swim | 2,500m — 5×300m at race pace, 200 cool-down |
| Tue | Bike intervals | 75 min with 4×6 min at threshold |
| Wed | Run tempo | 45 min with 25 min at half-marathon effort |
| Thu | Swim | 2,500m — race simulation, wetsuit if possible |
| Fri | Rest / Strength | 20 min light mobility |
| Sat | Brick: Bike → Run | 2 hr bike + 30 min run, full race nutrition test |
| Sun | Long run | 80 min at easy/moderate pace |
Week 10
Peak| Day | Workout | Details |
|---|---|---|
| Mon | Swim | 2,500m — 2×600m at race pace, 4×100m fast finish |
| Tue | Bike | 80 min with 3×10 min at race effort |
| Wed | Run | 40 min with 8×1 min at 10K pace |
| Thu | Swim | 2,000m open water or sighting practice |
| Fri | Rest | Full rest, focus on sleep |
| Sat | Brick: Bike → Run | 2.5 hr bike + 30 min run, race rehearsal |
| Sun | Long run | 85 min easy |
Week 11
Taper| Day | Workout | Details |
|---|---|---|
| Mon | Swim | 1,800m — 4×200m at race pace, easy cool-down |
| Tue | Bike | 50 min with 3×5 min at race effort |
| Wed | Run | 30 min easy with 4×30s strides |
| Thu | Swim | 1,500m easy with technique focus |
| Fri | Rest | Full rest |
| Sat | Brick: Bike → Run | 60 min bike + 15 min run, easy effort |
| Sun | Run | 40 min easy |
Week 12
Taper / Race Week| Day | Workout | Details |
|---|---|---|
| Mon | Swim | 1,200m easy with 4×50m at race pace |
| Tue | Bike | 30 min easy spin with 3×1 min pick-ups |
| Wed | Run | 20 min easy shakeout |
| Thu | Swim | 800m easy, course familiarization if possible |
| Fri | Rest | Full rest — prep gear, lay out race kit |
| Sat | Activation | 15 min easy bike + 10 min jog, shake out legs |
| Sun | 🏁 RACE DAY | Ironman 70.3 — trust your training! |
Key training principles
Brick workouts
Short, controlled bike-to-run sessions help you practise the transition and learn how your pacing feels. Build them only when the individual bike and run loads are already recoverable.
Progress from your current load
There is no universal safe weekly percentage increase. Compare this template with your recent training and adjust duration, frequency, and intensity rather than forcing a fixed progression.
Keep most work controlled
The schedule uses plenty of easy aerobic work and a smaller amount of purposeful intensity, but the appropriate balance depends on your background, phase, recovery, and response.
Recovery is training
Adaptation happens during rest, not during the workout. Prioritize sleep, nutrition, and easy days to let your body rebuild stronger.
Race simulation
Practice your nutrition plan, transitions, and pacing during training. Nothing new on race day — rehearse everything in advance.
Common mistakes to avoid
Skipping swim competence
Pool fitness alone does not establish open-water safety. Build technique and practise sighting and open-water skills with appropriate supervision.
Going too hard too early
Easy days should feel easy. Save your high-intensity effort for designated quality sessions.
Neglecting transitions
Practise T1 and T2 so equipment order, mounting, dismounting, and course rules are familiar rather than rushed.
Ignoring nutrition practice
Your gut needs training too. Practice eating and drinking during long sessions to avoid race-day GI issues.
Comparing to others
Follow YOUR plan. Social media training volumes are often exaggerated or irrelevant to your fitness level.
Nutrition & recovery basics
- Use longer sessions to test a personalized fueling and hydration plan; needs and tolerance vary by athlete, duration, intensity, weather, and product concentration
- Practise race-day products during selected long sessions and note gastrointestinal response
- Avoid forcing fluids; use thirst, conditions, sweat losses, event access, and professional guidance to shape a plan
- Eat regular meals and snacks that support recovery rather than relying on a universal post-workout window
- Make pre-race food changes only after testing them in training
- Ask a qualified sports dietitian for individualized advice, especially with medical conditions, medication, allergies, or a history of disordered eating
For detailed fueling strategies, check out our nutrition guides and the race nutrition calculator.
Safety and limitations
- This is general educational information, not an individualized prescription or medical clearance.
- The plan does not account for your training history, injury risk, heat acclimation, altitude, pregnancy, medication, chronic conditions, or the demands of a specific course.
- Open-water swimming should be practised with suitable supervision, visibility, conditions, and local safety procedures; do not swim alone.
- Check the current event athlete guide for distances, equipment rules, cutoffs, aid stations, and course changes.
Methodology
We organized the template around repeated exposure to all three disciplines, mostly controlled aerobic work, bike-to-run practice, planned easier weeks, course-relevant rehearsal, and a reduction in training stress before race week. These are planning principles rather than universal dose rules. The schedule was reviewed against current public-health guidance, current World Triathlon competition rules, and peer-reviewed reviews of endurance-training intensity distribution and the triathlon bike-to-run transition.
Sources
- Physical Activity Guidelines for Americans, 2nd edition — U.S. Department of Health and Human Services
- World Triathlon Competition Rules — World Triathlon
- Training intensity distribution in endurance athletes: a systematic review and network meta-analysis — Sports Medicine
- Bike-to-run transition in triathlon: a systematic review — Sports Medicine - Open
Substantively reviewed 2026-08-19.