An IRONMAN 70.3 takes real commitment, but the training is far more manageable to balance with work and family than a full-distance IRONMAN. That makes it the ideal starting point for athletes new to long-course racing. Here is how to tell if you are ready.
What Is An IRONMAN 70.3?
An IRONMAN 70.3 is a 1.2-mile swim, a 56-mile bike, and a 13.1-mile run, completed back to back. The distances add up to 70.3 miles, which is where the name comes from. A full-distance IRONMAN is exactly double: a 2.4-mile swim, a 112-mile bike, and a 26.2-mile run, for a total of 140.6 miles.
Most athletes finish an IRONMAN 70.3 in about 5 to 8 hours, compared with 10 to 17 hours for a full IRONMAN. If your sights are set on the full distance instead, our companion guide on how to know if you are ready to do an IRONMAN covers that step up.
Who Does IRONMAN 70.3 Triathlons?
College students, full-time parents, working professionals, and even octogenarians race IRONMAN 70.3 events. It is not just for the super fit and fast. It is for anyone who wants to test their limits, embrace a healthy lifestyle, and chase a life-changing goal. For those chasing endurance, it is a worthy challenge, and for those with a need for speed, it is a chance to race faster than an all-day full IRONMAN.
If you are considering one, think about your current fitness, athletic background, motivation, goals, time to train, and support system.
Ask Yourself A Few Key Questions
Have you done a triathlon before? If not, that is fine. Some athletes make a 70.3 their first triathlon, but you will likely enjoy it more, especially as a beginner, if you race a few shorter events first, like a sprint or Olympic. Those short-course races (about 1 to 3 hours, versus 5 to 8 for a 70.3) are perfect practice for race-day skills like transitions, pacing, and fueling before you step up.
Do you have single-sport experience? If you ran track or swam as a kid, you have a head start. If not, that is okay too. You will learn the basics of each sport, build good form, train consistently, and fuel properly to develop the endurance to swim 1.2 miles, ride 56, and run 13.1 while pacing the whole effort.
Not ready to take on all three yet? There is a relay option. Sign up with two or three teammates and each person does one leg (swim, bike, or run). It is a fun way to experience an IRONMAN 70.3 with friends, family, or a club.
What Training Can I Expect?
Moving from short-course to the 70.3 middle distance means more training volume, with swimming, cycling, and running several times a week. How many hours depends on your fitness, background, and goals. With a solid base you might follow a 16-week plan; newer endurance athletes may want around 20 weeks.
A typical build looks like 8 to 10 hours a week for 8 to 12 weeks (Base), then 10 to 13 hours a week for 6 to 8 weeks (Build), then a 2 to 3 week Taper as race day nears. You will work up to sessions like a 2,500 to 3,500-yard swim, a 3 to 4-hour ride, and a 90-minute to 2-hour run.
Swimming intimidates beginners the most, so drill work matters for form, technique, and controlled breathing. Our guides to essential freestyle drills and open-water skills help here. Some bike sessions can be indoors on a trainer, but ride outside too for handling, climbing, and riding near other athletes. You will also add brick workouts, running straight off the bike so your legs adapt to that heavy feeling and you can rehearse a smooth transition.
Fuel every session, especially the long ones, with a balance of fluid, carbohydrates, and electrolytes. Practicing eating and drinking on the go trains your gut and helps prevent stomach trouble on race day. See our endurance nutrition basics to build your plan. When you are ready to follow a structured schedule, IRONMAN's training plans include a 16-week path to your first 70.3.
Do I Need To Run A Half Marathon First?
It is not required, though the experience helps. Depending on your run background, you might build up to 10 to 12 miles in training. Some plans go by mileage and others by time, and here is why: an athlete running an 8-minute mile covers 13.1 miles in about 1 hour 44 minutes, while a 12-minute-mile pace takes about 2 hours 37 minutes. That gap in time on your feet is why many plans are built around time rather than distance. It is also a great reason to work with a coach, who can plan your workouts, balance training with life, and build your pacing and nutrition strategy.
What Race Should I Do?
There are more than 100 IRONMAN 70.3 races worldwide, across the United States, South America, Europe, Asia, Africa, and Australia. When picking your first, weigh the course type, time of year, location, support, and your own strengths. Are you a strong swimmer? Do you like climbing, or prefer flat and fast? Do you run better in heat or cool?
Swim settings vary: a river at events like IRONMAN 70.3 Chattanooga and Augusta, or the ocean and bays at IRONMAN 70.3 Oceanside and North Carolina. Bike courses range from flat (IRONMAN 70.3 Monterrey) to climbing (IRONMAN 70.3 Mallorca and Nice), and run courses from rolling (IRONMAN 70.3 Hawaii) to flat (IRONMAN 70.3 Rio de Janeiro). The IRONMAN Race Finder shows every option and lets you filter by location and date.
Frequently Asked Questions
What is an IRONMAN 70.3?
It is a long-course triathlon made up of a 1.2-mile swim, a 56-mile bike, and a 13.1-mile run, for a total of 70.3 miles. It is also called a half IRONMAN because it is exactly half the full-distance total of 140.6 miles.
How long is an IRONMAN 70.3?
The race is 70.3 miles in total: a 1.2-mile (1.9 km) swim, a 56-mile (90 km) bike, and a 13.1-mile (21.1 km) run, done in that order.
How long does it take to finish an IRONMAN 70.3?
Most athletes finish in about 5 to 8 hours, depending on fitness, course, and conditions. A full-distance IRONMAN typically takes 10 to 17 hours, with a 17-hour cutoff.
Is an IRONMAN 70.3 still an IRONMAN?
Yes. It is the middle or half distance in the IRONMAN family, half the length of a full IRONMAN, and a common first step into long-course racing.
Can a beginner do an IRONMAN 70.3?
Yes. Many first-timers complete a 70.3 with consistent training, and racing a sprint or Olympic triathlon first makes the experience smoother. A relay option lets you split the swim, bike, and run across a team.
Ready To Find Your Race?
If this sounds like your kind of challenge, the next step is choosing where to start. Browse the IRONMAN Race Finder to find a 70.3 that fits your calendar and your strengths, then follow a training plan to build toward the start line. Already eyeing what comes after? See how to know if you are ready to do a full IRONMAN.
Find your IRONMAN 70.3 →Brittany (Bevis) Vermeer is a journalist and triathlete (7x 70.3, 2x World Championship qualifier, 2x IRONMAN) sharing practical tips and real-life experience to help athletes succeed.