16-Week Half Ironman Training Plan for Beginners
Complete 16-week 70.3 training plan for first-time half ironman athletes. Week-by-week schedule for 1.9km swim, 90km bike, and 21.1km run.
A 16-week Half Ironman training plan requires 8-12 hours of weekly training, building from aerobic base through race-specific long course preparation for the 1.9km swim, 90km bike, and 21.1km run.
The 70.3 distance represents a significant step up from Olympic triathlon—you'll be racing for 4-7 hours. This plan systematically builds the endurance and race-specific fitness you need.
Training Plan Overview
Weekly Volume Progression
| Week | Phase | Total Hours | Focus |
|---|---|---|---|
| 1-4 | Base | 8-9 hours | Aerobic foundation |
| 5-8 | Build 1 | 9-11 hours | Volume increase |
| 9-12 | Build 2 | 10-12 hours | Race-specific intensity |
| 13-14 | Peak | 11-13 hours | Longest sessions |
| 15-16 | Taper | 6-8 hours | Recovery and prep |
Training Distribution
| Discipline | Sessions/Week | Weekly Time |
|---|---|---|
| Swim | 2-3 | 2-2.5 hours |
| Bike | 2-3 | 4-5 hours |
| Run | 2-3 | 2.5-3.5 hours |
| Brick | 1 | Included in bike/run |
| Strength | 1-2 (optional) | 30-45 min |
Week-by-Week Breakdown
Weeks 1-4: Base Phase
Focus: Build aerobic foundation across all three disciplines
Sample Base Week (Week 3, ~9 hours):
| Day | Session | Duration | Intensity |
|---|---|---|---|
| Mon | Swim technique | 45 min | Easy |
| Tue | Easy run | 40 min | Zone 2 |
| Wed | Bike endurance | 75 min | Zone 2 |
| Thu | Swim endurance | 45 min | Easy-Moderate |
| Fri | Rest | - | - |
| Sat | Long bike | 2 hours | Zone 2 |
| Sun | Long run | 60 min | Zone 2 |
Key Points:
- All training at conversational pace
- Build swim technique foundation
- Establish consistent training routine
- Practice basic nutrition on long sessions
Weeks 5-8: Build Phase 1
Focus: Increase volume, introduce first long bricks
Sample Build 1 Week (Week 6, ~10 hours):
| Day | Session | Duration | Intensity |
|---|---|---|---|
| Mon | Swim threshold | 50 min | Hard |
| Tue | Run tempo | 45 min | Moderate-Hard |
| Wed | Bike tempo | 75 min | Moderate |
| Thu | Easy swim | 40 min | Easy |
| Fri | Rest | - | - |
| Sat | Brick: Bike + Run | 2.5 hrs + 30 min | Race effort |
| Sun | Long run | 70 min | Zone 2 |
Key Points:
- First brick workouts become longer
- Introduce threshold sessions
- Practice race nutrition every long session
- Build mental confidence
Weeks 9-12: Build Phase 2
Focus: Race-specific intensity, longest training sessions
Sample Build 2 Week (Week 10, ~11 hours):
| Day | Session | Duration | Intensity |
|---|---|---|---|
| Mon | Swim intervals | 55 min | Hard |
| Tue | Run intervals | 55 min | Hard |
| Wed | Bike sweet spot | 90 min | Moderate-Hard |
| Thu | Easy swim | 45 min | Easy |
| Fri | Rest or easy spin | 30 min | Very easy |
| Sat | Long brick | 3 hrs + 40 min | Race effort |
| Sun | Long run | 80 min | Easy-Moderate |
Key Points:
- Longest brick workouts
- Race simulation sessions
- Fine-tune nutrition strategy
- Practice race pacing
Weeks 13-14: Peak Phase
Focus: Highest training volume, race simulation
Sample Peak Week (Week 13, ~12 hours):
| Day | Session | Duration | Intensity |
|---|---|---|---|
| Mon | Swim race pace | 55 min | Hard |
| Tue | Run tempo | 60 min | Moderate-Hard |
| Wed | Bike threshold | 100 min | Hard |
| Thu | Easy swim | 45 min | Easy |
| Fri | Rest | - | - |
| Sat | Race simulation | 3.5 hrs + 50 min | Race effort |
| Sun | Long run | 90 min | Easy |
Weeks 15-16: Taper
Focus: Reduce volume, maintain intensity, arrive fresh
Race Week (Week 16):
| Day | Session | Duration | Intensity |
|---|---|---|---|
| Mon | Easy swim | 30 min | Easy |
| Tue | Easy run with strides | 25 min | Easy |
| Wed | Easy bike | 40 min | Easy |
| Thu | Easy swim | 20 min | Easy |
| Fri | Rest | - | - |
| Sat | Light jog | 15 min | Very easy |
| Sun | RACE DAY | - | - |
Learn more about tapering: Triathlon Taper Guide
Key Workouts Explained
Long Bike Sessions
Build progressively to race distance and beyond:
| Week | Long Bike Duration | Notes |
|---|---|---|
| 1-4 | 90-120 min | Zone 2 |
| 5-8 | 2-2.5 hours | Include tempo blocks |
| 9-12 | 2.5-3.5 hours | Race simulation |
| 13-14 | 3.5-4 hours | Longest ride |
| 15-16 | 40-60 min | Taper |
Long Run Sessions
| Week | Long Run Duration | Notes |
|---|---|---|
| 1-4 | 50-70 min | Zone 2 |
| 5-8 | 70-85 min | Mostly Zone 2 |
| 9-12 | 80-100 min | Include tempo |
| 13-14 | 100-120 min | Longest runs |
| 15-16 | 30-45 min | Taper |
Brick Workouts
Essential for 70.3 success—practice running off the bike:
| Phase | Brick Format |
|---|---|
| Base | 90 min bike + 20 min run |
| Build 1 | 2-2.5 hrs bike + 30 min run |
| Build 2 | 3 hrs bike + 40 min run |
| Peak | 3.5 hrs bike + 50 min run |
Race Day Targets
Finish Time Estimates
| Level | Swim | T1 | Bike | T2 | Run | Total |
|---|---|---|---|---|---|---|
| Beginner | 40-50 min | 5-7 min | 3:15-3:45 | 3-5 min | 2:15-2:45 | 6:30-7:30 |
| Intermediate | 32-40 min | 3-5 min | 2:45-3:15 | 2-3 min | 1:50-2:15 | 5:15-6:15 |
| Advanced | 28-32 min | 2-3 min | 2:25-2:45 | 1-2 min | 1:35-1:50 | 4:30-5:15 |
Use our 70.3 Calculator to estimate your finish time.
Nutrition Strategy
Training Nutrition
For sessions over 90 minutes:
- Carbohydrates: 60-90g per hour
- Fluids: 500-750ml per hour
- Practice: Same products as race day
Race Day Nutrition
| Leg | Strategy |
|---|---|
| Swim | Nothing during |
| Bike | 60-90g carbs/hour, 500-750ml fluid/hour |
| Run | 30-60g carbs/hour, fluids at aid stations |
Read more: Half Ironman Nutrition Plan
Common Mistakes to Avoid
1. Too Much Intensity
The mistake: Hard sessions too often
The fix: 80% of training at easy pace, save hard efforts for key sessions
2. Ignoring Long Sessions
The mistake: Skipping or shortening long workouts
The fix: Prioritize the weekly long bike and brick—they're non-negotiable
3. Poor Nutrition Practice
The mistake: Not testing race nutrition
The fix: Practice fueling on every long session
4. Racing Too Hard on the Bike
The mistake: Pushing bike to the limit
The fix: Target 70-75% FTP to save legs for the run
Learn more: Half Ironman Pacing Strategy
Prerequisites for This Plan
Before starting, you should be able to:
- Swim 1,000m continuously
- Bike 90 minutes comfortably
- Run 45-60 minutes
- Train 6-8 hours per week
If you need more preparation time, consider our 20-Week Half Ironman Plan.
Related Resources
- 70.3 Pace Calculator - Estimate your finish time
- Half Ironman First Timer Guide - Complete beginner's guide
- Half Ironman Nutrition Plan - Race day fueling
- Brick Workouts for Triathlon - Master bike-to-run
- Triathlon Training Guide - Training principles
- Half Ironman Glossary - Key terms explained
- 24-Week Ironman Training Plan - Step up to full distance
- First Ironman Complete Guide - Full Ironman preparation