Triathlon••7 min read
24-Week Half Ironman Training Plan: 6-Month Build
Comprehensive 24-week 70.3 training plan with maximum base building. Ideal for first-time long-course athletes who want the safest progression.
A 24-week Half Ironman training plan offers the most gradual progression for first-time 70.3 athletes, allowing proper aerobic development and injury prevention over six months.
Six months of preparation provides the time to build a rock-solid foundation, develop proper technique, and arrive at race day confident and injury-free.
Who Should Choose 24 Weeks?
Perfect For
- Complete triathlon beginners
- Athletes new to endurance sports
- Those with history of overuse injuries
- Busy professionals with variable schedules
- Anyone prioritizing longevity over speed
- Athletes wanting maximum preparation confidence
When Shorter Plans Work
- Experienced endurance athletes
- Those with strong aerobic base
- Athletes who've completed Olympic+ distance
- Limited time until race
Training Plan Overview
6-Month Structure
| Month | Weeks | Phase | Hours/Week |
|---|---|---|---|
| 1 | 1-4 | Foundation | 5-7 |
| 2 | 5-8 | Base 1 | 7-8 |
| 3 | 9-12 | Base 2 | 8-9 |
| 4 | 13-16 | Build 1 | 9-11 |
| 5 | 17-20 | Build 2 | 10-12 |
| 6 | 21-24 | Peak/Taper | 12 → 6 |
Monthly Training Focus
| Month | Primary Focus | Key Sessions |
|---|---|---|
| 1 | Technique, routine | Drills, easy volume |
| 2 | Aerobic base | Zone 2 emphasis |
| 3 | Extended endurance | Longer sessions |
| 4 | First intensity | Threshold introduction |
| 5 | Race-specific | Long bricks, simulation |
| 6 | Peak and taper | Longest sessions, then rest |
Month-by-Month Breakdown
Month 1: Foundation (Weeks 1-4)
Goals:
- Establish training routine
- Build basic fitness
- Learn proper technique
- Create good habits
Sample Week (Week 3):
| Day | Session | Duration |
|---|---|---|
| Mon | Swim drills | 35 min |
| Tue | Easy run | 30 min |
| Wed | Rest | - |
| Thu | Easy bike | 50 min |
| Fri | Swim technique | 30 min |
| Sat | Long bike | 75 min |
| Sun | Long run | 40 min |
Total: ~6 hours
Month 2: Base Building 1 (Weeks 5-8)
Goals:
- Increase volume gradually
- Build aerobic capacity
- Introduce first bricks
- Develop swimming efficiency
Sample Week (Week 6):
| Day | Session | Duration |
|---|---|---|
| Mon | Swim technique + endurance | 45 min |
| Tue | Easy run | 40 min |
| Wed | Bike endurance | 65 min |
| Thu | Rest | - |
| Fri | Swim endurance | 40 min |
| Sat | Brick: Bike + Run | 80 + 15 min |
| Sun | Long run | 50 min |
Total: ~7.5 hours
Month 3: Base Building 2 (Weeks 9-12)
Goals:
- Extended long sessions
- Build mental endurance
- Practice basic nutrition
- Strengthen aerobic engine
Sample Week (Week 10):
| Day | Session | Duration |
|---|---|---|
| Mon | Swim endurance | 50 min |
| Tue | Easy run | 45 min |
| Wed | Bike endurance | 75 min |
| Thu | Easy swim | 35 min |
| Fri | Rest | - |
| Sat | Long brick | 100 + 20 min |
| Sun | Long run | 60 min |
Total: ~8.5 hours
Month 4: Build 1 (Weeks 13-16)
Goals:
- Introduce threshold training
- Longer brick workouts
- Practice race nutrition
- Build race-specific fitness
Sample Week (Week 14):
| Day | Session | Duration |
|---|---|---|
| Mon | Swim CSS intervals | 50 min |
| Tue | Run tempo | 50 min |
| Wed | Bike tempo | 80 min |
| Thu | Easy swim | 40 min |
| Fri | Rest | - |
| Sat | Long brick | 2.5 hrs + 30 min |
| Sun | Long run | 70 min |
Total: ~10 hours
Calculate your swim zones: CSS Calculator
Month 5: Build 2 (Weeks 17-20)
Goals:
- Race simulation sessions
- Longest training weeks
- Fine-tune nutrition strategy
- Build confidence
Sample Week (Week 18):
| Day | Session | Duration |
|---|---|---|
| Mon | Swim threshold | 55 min |
| Tue | Run intervals | 55 min |
| Wed | Bike sweet spot | 90 min |
| Thu | Easy swim | 45 min |
| Fri | Rest | - |
| Sat | Race simulation | 3.5 hrs + 45 min |
| Sun | Long run (progressive) | 85 min |
Total: ~11.5 hours
Month 6: Peak & Taper (Weeks 21-24)
Weeks 21-22: Peak Phase
Highest training volume:
| Session | Week 21 | Week 22 |
|---|---|---|
| Long Brick | 4 hrs + 50 min | 3.5 hrs + 45 min |
| Long Run | 100 min | 90 min |
| Weekly Hours | 12-13 | 11-12 |
Weeks 23-24: Taper
| Week | Volume | Focus |
|---|---|---|
| 23 | 60% of peak | Maintain intensity, reduce volume |
| 24 | 40% of peak | Fresh for race day |
Learn more: Triathlon Taper Guide
Long Session Progression
Long Bike Build
| Month | Duration | Notes |
|---|---|---|
| 1 | 60-75 min | Building comfort |
| 2 | 75-90 min | Zone 2 focus |
| 3 | 90-120 min | Add nutrition practice |
| 4 | 2-2.5 hours | Include tempo blocks |
| 5 | 2.5-3.5 hours | Race simulation |
| 6 | 4 hours → taper | Peak then reduce |
Long Run Build
| Month | Duration | Notes |
|---|---|---|
| 1 | 35-45 min | Easy, consistent |
| 2 | 45-55 min | Zone 2 |
| 3 | 55-65 min | Building endurance |
| 4 | 65-75 min | Some tempo |
| 5 | 80-95 min | Race simulation |
| 6 | 100 min → taper | Peak then reduce |
Brick Workout Build
| Month | Format | Notes |
|---|---|---|
| 2 | 75 min bike + 15 min run | Introduction |
| 3 | 90 min bike + 20 min run | Building |
| 4 | 2 hrs bike + 25 min run | Race effort |
| 5 | 3 hrs bike + 40 min run | Simulation |
| 6 | 4 hrs bike + 50 min run | Peak |
Benefits of 24-Week Preparation
Physical Benefits
- Stronger aerobic base: More time for mitochondrial development
- Lower injury risk: Gradual progression prevents overuse
- Better technique: Time to refine form in all three sports
- Heat adaptation: If racing in summer, body adapts better
- Nutrition mastery: More opportunities to practice fueling
Mental Benefits
- Confidence: Know you're fully prepared
- Race experience: More long sessions = more race simulation
- Reduced anxiety: No rushing through preparation
- Flexibility: Life interruptions don't derail your plan
Practical Benefits
- Schedule flexibility: Miss a week? No crisis
- Recovery time: More rest weeks built in
- Learning curve: Time to understand your body
- Equipment testing: Thoroughly test all race gear
Recovery Week Schedule
Every 4th week is a recovery week:
- Reduce volume 30-40%
- Maintain frequency
- All easy intensity
- Extra sleep
Recovery weeks: 4, 8, 12, 16, 20
Race Time Calculator
Use our 70.3 Calculator to estimate your finish time based on training paces.
Related Resources
- 16-Week Half Ironman Plan - Standard timeline
- 20-Week Half Ironman Plan - Moderate extension
- Half Ironman First Timer Guide - Complete beginner guide
- Half Ironman Nutrition Plan - Race day fueling
- Triathlon Base Building - Foundation phase details
- Half Ironman Glossary - Key terms