Ironman 70.3 Swim, Bike, and Run Training
Summary
Training for an Ironman 70.3 means preparing your body and mind to handle three endurance sports back to back. This guide walks you through how to structure your weekly plan, build your fitness in each discipline, and approach race day with confidence. Whether you’re aiming for a finish or a personal best, the right training strategy will help you get there.
How to Train for an Ironman 70.3
Signing up for your first Ironman 70.3 is exciting—but also overwhelming. With a 1.9 km swim, 90 km bike, and 21.1 km run ahead of you, it’s easy to wonder where to begin. The key to success isn’t elite ability—it’s building consistent endurance, learning how to pace yourself, and developing comfort across swim, bike, and run.
Most beginners follow a 16 to 24-week training plan, allowing time for steady progress, peak fitness, and recovery. The best plans include a variety of sessions that cover intensity, endurance, technique, and race simulation.
Don’t think of training as just logging hours. Instead, think of it as developing the skills to complete 70.3 miles efficiently and confidently.
What Exactly Is an Ironman 70.3?
Known as a Half Ironman, the race totals 70.3 miles:
Swim: 1.9 kilometers (1.2 miles)
Bike: 90 kilometers (56 miles)
Run: 21.1 kilometers (13.1 miles)
For most first-time triathletes, total finish times range from 5.5 to 8 hours. It’s a long day—but one you can complete with the right approach to training.
Each discipline presents its own challenges. The swim requires composure and technique, the bike demands pacing and fueling, and the run tests your mental and physical endurance. You’ll need to develop strength in each while practicing the transitions that tie them together.
Building a Weekly Structure
A well-balanced Ironman 70.3 week includes key endurance workouts, targeted intensity sessions, and adequate recovery. The goal is to touch each discipline multiple times per week without burning out.
A typical week might look like:
2 swims (one technique, one endurance)
3 bikes (including long ride and intervals)
3 runs (long run, threshold, and brick)
1 rest or active recovery day
This structure provides enough volume and variety to prepare your body while allowing time to absorb training stress. If you’re short on time, combining sessions—like brick workouts—can help.
Ironman 70.3 Swim Training
Many beginners fear the swim more than the other two disciplines. That’s normal. The open water environment, crowded starts, and longer distance can be intimidating. The solution? Practice and preparation.
Aim to swim two to three times per week, mixing technique drills with aerobic endurance work. Improving your efficiency in the water has a direct impact on your confidence and race-day energy levels.
Focus on:
Stroke efficiency: Include drills like catch-up, fingertip drag, and sculling
Bilateral breathing: It helps you stay relaxed and balanced
Sighting: Practice lifting your head every 6–8 strokes to simulate open water
As race day nears, make time for open water practice. This builds confidence, especially if you're using a wetsuit. Try to simulate race conditions whenever possible—swimming in a group, dealing with chop, and sighting on landmarks.
Your long swim should build to at least 2,000–2,500 meters by peak training. Steady pacing is more valuable than speed here—train to swim relaxed and strong.
Ironman 70.3 Bike Training
The bike leg makes up the largest portion of your race and your training time. It's where pacing and nutrition have the biggest impact. Many beginners go too hard on the bike, only to suffer during the run. Instead, train to ride efficiently, fuel smartly, and conserve enough energy to run well.
Ride at least three times per week, including:
A long endurance ride, gradually building to 3.5–4 hours
A tempo or threshold session, focused on steady pressure in Zone 3
A short recovery ride or brick session
Use long rides as race simulations. Test your bike nutrition, hydration intervals, and pacing strategy. If you have a power meter or heart rate monitor, learn your target race zone and practice staying in it. Use the FLJUGA calculator to calculate your training zones.
Try to ride outdoors when possible, especially on terrain similar to your race. Hills, wind, and road conditions are part of the challenge. Indoors, you can focus more on structure—but race day happens outside, so get used to it.
Ironman 70.3 Run Training
The final leg is where your training shows its true value. Running well off the bike takes more than fitness—it takes smart pacing, good fueling, and strong mental focus.
You’ll want to build to three or four runs per week, including:
Long runs of 75–120 minutes at a steady Zone 2 effort
Threshold runs with intervals in Zone 4 to improve running economy
Brick runs of 20–30 minutes off the bike, teaching your legs to adapt
Optional recovery jogs for blood flow and aerobic maintenance
Pacing is everything. Many athletes ruin their race by starting the run too fast. Train yourself to hold back in the first 5K. Build control, not just speed.
By peak training weeks, your long run should reach at least 18–21 km. You don’t need to run a full half marathon every weekend—just enough to build the confidence and stamina to carry you through the final stage of the race.
The Role of Brick Workouts
Brick sessions are workouts where you train two disciplines back-to-back, usually bike-to-run. These are essential for teaching your body how to manage transitions and perform under cumulative fatigue.
Start small—maybe a 60-minute ride followed by a 15-minute jog—and build from there. These sessions simulate race day fatigue and improve mental focus when the body is tired.
Include at least one brick session per week in your mid to late build phase. You’ll learn how your body responds, how your legs feel, and what pacing strategy works best for you.
When to Taper
Tapering is often overlooked but critically important. It gives your body time to recover from hard training and arrive on race day rested, sharp, and ready. Start tapering about 2–3 weeks before your race.
The volume should decrease, but keep some intensity:
Cut weekly training time by 30–50%
Keep short intervals to maintain fitness
Prioritize extra sleep, clean nutrition, and reduced stress
Don’t cram last-minute sessions. Trust your training. The work is done.
Frequently Asked Questions
How many hours a week should I train?
Most beginner Ironman 70.3 athletes train between 8 and 12 hours weekly. Peak weeks may reach 14, depending on your background and goals.
Do I have to train in open water?
It’s strongly recommended. Open water swimming builds specific skills that pool training can’t replicate.
Can I walk during the run?
Absolutely. Many first-timers walk through aid stations or use a structured run/walk method.
What’s the biggest mistake beginners make?
Pacing errors. Overcooking the bike is the most common issue, leading to a painful run.
Final Thoughts
Training for an Ironman 70.3 isn’t just about logging swim, bike, and run sessions. It’s about developing the endurance, pacing, and mindset to complete one of the most rewarding challenges in endurance sport. Respect the distance. Commit to the process. And remember, the goal isn’t just to finish—it’s to finish strong, steady, and proud.
Are you ready to train smart and go the distance?
Always consult with a medical professional or certified coach before beginning any new training program. The information provided is for educational purposes only and is not a substitute for personalized advice.
