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Triathlete’s Complete Guide on How to Train for an Ironman

While racing 140.6 miles of swimming, biking, and running may feel like a daunting task, our editors have compiled our vast resources into a comprehensive guide on how to train for an Ironman.

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Knowing how to train for an Ironman isn’t easy. Ironman training is more than just a lot of swim, bike, and run workouts—as you’ll soon discover, there are many parts of the puzzle. But before we dive into what you need to know about Ironman training, from gear to training plans to choosing your race, let’s first answer two basic questions: What is an Ironman, and how far is an Ironman?

What is an Ironman triathlon?

Most people are familiar with the iconic Ironman World Championship race, which typically takes place in Kona every October (although due to COVID, it has not taken place since Oct. 2019; the 2021 race has been rescheduled to May 2022 in St. George, Utah).

But the race in Hawaii isn’t the only Ironman out there. Races are held around the world, both as part of the Ironman branded race series and those put on by other race organizations, known as “iron-distance triathlons.” All Ironman and Iron-distance races cover the same distances:

How far is an Ironman triathlon?
Swim 2.4 miles
Bike 112 miles
Run 26.2 miles
TOTAL 140.6 miles

It’s important to note that Ironman 70.3 races, while also carrying the Ironman name, are not a “full” Ironman. Instead, they are what is known as a “half-iron distance,” where the swim, bike and run distances are halved to cover a total of 70.3 miles. (Still an impressive feat, to be sure, and a great starting goal for those new to long-course triathlon racing!)

It can often be the Ironman swim distance that deters or intimidates beginners—and those who are new to swimming will certainly want to master the basics in order to feel comfortable and confident. The good news? With the right coaching, feedback, and guidance, you can make progress both technically and physically while training for an Ironman. It just takes time and patience.

RELATED: Our Complete Guide to Triathlon Swimming

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What’s the average Ironman race time?

The average Ironman finishing time is between 12 to 14 hours, with approximately 10% of the race spent swimming, 50% of the race spent on the bike, and 38% of the race spent running. The remaining 2% is spent in transition—from swim to bike, known as T1, and bike to run, or T2.

For this reason, many athletes and coaches will advocate spending at least 50% of your training time for an Ironman triathlon on the bike. However, this can differ depending on the time athletes have available, background, experience, climate and terrain where you live, and personal preferences.

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Can I do an Ironman?

Going from couch to Ironman can be a daunting task, but it’s not impossible, and many have successfully achieved it. When faced with the question of “Who does Ironman triathlon?” most people assume that it’s the bastion of the ultra-fit and ultra-lean. This is actually not the case! There are a growing number of first-timers doing Ironman, and people aged 13 to 89 have finished an Ironman or iron-distance triathlon. Almost anyone can do an Ironman if they work hard and follow a smart training plan.

However, before deciding to sign up for an Ironman triathlon, it’s a good idea to closely examine a few things:

  • Your motivation for doing it
  • The time available to train for Ironman
  • Your current fitness
  • Injury history
  • Previous athletic background

Taking an honest and realistic approach to training for Ironman now will save you stress in the future. If you’re new to triathlon or prone to injury when exercising, it’s a good idea to spend some time strengthening your body and gradually building your endurance so that you can handle long workouts and an even longer race.

RELATED: 8 Questions to Determine If You’re Cut Out For Ironman

It’s also a good idea to check with your primary healthcare provider before embarking on your Ironman training journey. You’ll be asking a lot of your body while preparing for the race, and a checkup with your physician can confirm it’s up for the task.

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Which Ironman race should I do? 

Deciding on which race to do—especially if it’s your first Ironman triathlon—is no small decision. Don’t be afraid to take the time to do the necessary research. You can look up the best or easiest Ironman for beginners, but that doesn’t always mean that’s the best or easiest Ironman for you. Some steps to help you decide which Ironman triathlon is the best for you:

  • Ask more experienced athletes, friends, and coaches what race they’d recommend for a first-time Ironman.
  • Do your due diligence on the course, terrain, the expected temperatures/weather conditions, and the gear/equipment you might need.
  • Think about the conditions under which you do best: Are you someone who thrives in the heat and humidity, or would you prefer to dive into a 60 degree F swim? Do you enjoy riding and running on undulating or hilly terrain, or are fast, flat courses more your thing?
  • Consider what is most important to you on race day: Do you want to do your hometown course, or travel to a destination race to make a vacation out of it? Would you like your friends and family there to cheer you on, or would you rather fly solo? These factors may seem trivial, but they can be really important to your race day experience.

Among the most popular Ironmans for beginners in the U.S. are Ironman Florida in Panama City Beach in November, Ironman Texas in The Woodlands (back to its usual slot in April in 2022, but this year in October due to COVID), and Ironman Arizona in Tempe in November. It might come as no surprise to see that all three of these courses are flat, which is certainly what attracts newcomers.

More seasoned athletes like these courses too, because it allows them to chase a personal record (PR). Because these races are so popular, entries get snapped up super fast. In fact, for races like Ironman Arizona, there’s often tough competition to sign up to volunteer at the race, because volunteers get first shot at registering when race entries open up for the following year. (Yes, you read that right!)

No matter what race you decide to enter, you’ll likely need to register a year in advance. Ironman is not something to be taken lightly—both from a fitness and a financial perspective. The Ironman registration fee alone is $800, and you haven’t even started buying the equipment you’ll need (more on that below).

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(Photo: Getty Images)

How much time does it take to train for an Ironman? 

We are often asked the question: “How long does it take to train for an Ironman?” The answer is always the same: “It depends.”

Some people say you should give yourself a year to properly train for an Ironman. Given that most Ironman races require you to sign up a year in advance (as we said earlier), it’s not a bad idea to start out with some easy base/foundation training shortly after signing up. This will also help you to capitalize on your sky-high motivation—there’s nothing like signing up for a race to get you inspired to get moving!

If you’re someone who’s already fit and active with experience in at least one of the three sports, then you’ve certainly got a head start on training for an Ironman. For those with a solid base under them already, a 12-week Ironman training plan is a good idea, at the very least. And when we say solid base, this typically means you’re comfortable swimming for an hour three times a week, you’re riding three times a week, and you’re running three or four times a week.

But if you’re new to swimming, cycling, and running, you’ll want to give yourself plenty of time to prepare for the race. How long? At the very least, a first-timer should follow a 24-week Ironman training plan, as it will give an athlete time to get accustomed to the three sports (and juggling all of them with life) while gradually building the fitness required to cover 140.6 miles.

There is no hard and fast rule on how many hours per week it takes to train for an Ironman. Everyone is different and has different commitments and schedules, so be flexible with your training and fit it in around your work, family, and social commitments. One of the biggest mistakes newcomers can make is trying to pack as much training into their week as possible. To create more hours in the day, they sometimes wake up earlier or go to bed later, completely overlooking the fact that recovery time—and sleep—is one of the most important elements of Ironman training. It’s not the training sessions that will make you fitter and faster, but the recovery and subsequent adaptation from those sessions that’ll really see you making the gains.

With this in mind, take a long, hard look at your average week and be realistic about how much spare time you have to fit in swim, bike, and run workouts. If you think that number is close to 10 hours, start out with six to eight hours and see how that goes. There are many accomplished age-group athletes who have achieved great things on 10 hours of training a week or less.

The golden rule of Ironman training

You’ll hear experienced Ironman athletes and coaches agree on the golden rule of Ironman training—consistency is king. While it can be great to knock a key workout out of the park, it’s better to hit all of your workouts consistently than to nail one and have to skip the next three or four days because you’re feeling wrecked. Meter your energy and commit to your Ironman training plan over the long-term, so that you are able to gradually build your fitness. If you ask any experienced triathlete about how they train for an Ironman, they’ll tell you the boom-and-bust approach can often lead to injury, burnout, and loss of motivation and enjoyment.

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(Photo: Getty Images)

Do I need a coach to train for an Ironman?

At the very least, it’s a good idea to follow an Ironman training plan (read on for some of our favorites). These are tried-and-true schedules that thousands of athletes have followed to arrive at the start line happy and healthy. Trying to make your workout schedule on the fly, especially if you have little or no triathlon experience, can quickly become overwhelming—and worse yet, it can lead to injury, burnout, or a really bad race experience.

But what if the training plans available don’t fit with your schedule or needs? You might prefer the individualized advice you get from a triathlon coach, who can give you specific advice on how to train for an Ironman. In addition to writing workouts just for you, a coach can answer all your questions about training for an Ironman, what to expect on race day, and how to troubleshoot any issues (like injuries) as they arise.

RELATED: Our Guide to Coaching Styles

If you have access to a local triathlon team or a good group of training buddies, you can also ask for their advice on training and racing. Training buddies make your training and your overall experience far more sociable and enjoyable—and triathletes love to share their knowledge with newcomers.

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Ironman training plans 

It is always a good idea to follow a structured training plan that has been designed by a coach with many years of experience. Well-structured Ironman training plans will factor in periodization, which is the term given to the many phases of training in any given year. Typically, these are structured as follows:

Ironman Training Stages
Base Usually the winter months, this time is spent doing mostly aerobic endurance training to help develop a fitness base. As they say: “the bigger your base, the faster the race!” Think of this time as laying the foundations for the season ahead.
Build This is typically six to 12 weeks before the race (depending on the athlete and their experience). Training will start to include more higher-intensity work and race-pace efforts. You should also start working in some brick sessions here (swim to bike and/or bike to run).
Race Race-specific work, including race pace work, open-water swimming, practicing nutrition and transition rehearsal.
Recover Often referred to as the off-season or post-season, this is the time when athletes will take anything from two to six weeks off from structured training in favor of sports other than swim, bike, and run.

Beginner Ironman training plans should take into account the fact that you are new to the sport and build volume slowly. As already outlined above, be sure to choose a plan that suits your time commitments, and make sure it’s well balanced. If you are a weaker swimmer but an experienced runner, don’t shy away from spending more time in the water and less time out running, although be aware that learning to run off the bike is very different to standalone running and can take time to get used to.

Our most popular Ironman training plans:

Your First Ironman Training Plan
24-Week Ironman Training Plan
The 10-Hour Week Ironman Training Plan
Super SImple 20 Week Ironman Training Plan

RELATED: How to Read Your Training Plan

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(Photo: Getty Images)

What Gear Do I Need for an Ironman Race?

Knowing what you need for an Ironman race is no small question. Did we mention this sport is extremely gear-heavy? Perhaps the best piece of advice we could give you to begin with is that you don’t need everything straight away. Let’s break it down into three categories: basic, intermediate, and advanced.

Click on each category below for Triathlete’s handpicked gear roundups and buyer’s guides for our editors’ best recommendations:

Basic

Wetsuit (best of men’s and women’s)

You’ll need a wetsuit not only for warmth, but for increased buoyancy, which leads to speed.

Swim cap

A swim cap will keep your hair from flying everywhere while you swim, but it’ll also keep you warm, and for 99% of Ironman races, you’ll need to wear one on race day.

Goggles

Triathlon swimming goggles typically have more visibility and protection for open-water swimming.

Trisuit or tri top/shorts

Tri-specific clothing will have padded shorts and material that you can wear the entire race without changing, if preferred.

Bike

While you don’t need a tri-specific bike, at the Ironman distance a tri bike will be faster, more comfortable and recruit muscles that won’t interfere with your run.

Helmet

All Ironman events require a helmet on the bike—more expensive helmets will be lighter, more ventilated and/or more aerodynamic.

Sunglasses

While not required, sunglasses will let you see better and protect your eyes on the bike. A good pair will be ventilated enough to let you wear them on the run as well.

Run shoes

In iron-distance racing, some people prefer lightweight run shoes, while others prefer more substantial trainers. Either way, you need shoes that will withstand the rigors of Ironman training miles.

Race belt

A race belt will help you on race day by keeping your number on your at all times from the bike to the run (depending on the rules) without wasting time pinning it to your clothing.

Anti-chafe lube/cream

In Ironman racing, anti-chafe lube is essential. Use it in places where you contact the saddle, where your body has natural creases, or where friction is possible.

Water bottle(s)

Iron-distance training and racing requires lots of hydration. Be sure to get a hydration storage system that lets you take more than you think you might need.

Intermediate

As above, plus:

Bike shoes

Cycling-specific shoes and tri-specific shoes will attach to your specialty pedals and allow better power transfer and comfort. Tri-specific shoes will have features like quick on-and-off, drainage, and more.

Transition bag

A transition bag will help you organize all of the gear listed here while you’re both training and racing. Better organization means less chance of forgetting something when it matters.

Tri saddle

A tri-specific saddle will be shaped in a way that best fits a triathlete’s position on a bike with aerobars.

Indoor bike trainer

Unless you live in a place with year-round good weather, an indoor bike trainer is an essential way to get in quality workouts when the weather is bad or the conditions are unsafe for riding outside.

Smartwatch

Today’s smartwatches will not only track time and distance, but also help prescribe workouts, give biofeedback, track sleep, connect to your bike, and give pool and open-water swimming data.

Aerobars

These speciality handlebars place the rider in a more aerodynamic and (ideally) more comfortable position for long-distance training and racing.

Bike hydration system

Typically located between the aerobars, inside the frame, or behind the saddle, a bike hydration system will allow you to carry more fluid in a way that’s easy to reach and won’t affect bike handling.

Advanced

Aero helmet

An aero helmet will simply reduce the drag as you race on your bike—assuming you can hold the proper aero position for the great majority of your race.

Race wheels

These aerodynamic, carbon wheels will not only allow you to ride faster, but can also increase comfort—depending on the rim depth and hub/spoke construction.

Cycling or running power meter

During training, a cycling or running power meter will help you get the most objective training data—regardless of conditions or terrain. While racing, they can help you with pacing and properly doling out your effort.

Need even more help on where to prioritize your spending? Check out Triathlete’s comprehensive, illustrated guide to buying tri gear.

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What to eat while training for an Ironman

Knowing how to eat for Ironman training can be a daunting task: you’ll be training a lot, which is going to make you want to eat a lot, which is definitely not the best way forward. You’re certainly going to be hungry, especially if you are increasing your activity levels above what you’re used to. But that doesn’t mean you should eat everything you’re craving. Food is fuel, and when you’re training for an Ironman, you’ll want to put the best fuel in your body.

The key to fueling for Ironman training is to make sure that you are taking in the right quantity and quality of food and drink to execute each workout. While there are definitely different schools of thought regarding how much of each macro-nutrient (protein, carbs, fats) you should eat for Ironman training, the general consensus in Ironman nutrition plans is that triathletes should eat a good balance of protein, carbs, and healthy fat to stay full and well-fueled for as long as possible.

RELATED: Practical Guidelines for Fueling and Nutrition

The most important meal is the one you eat after longer, harder training sessions, as it sets the stage for the next workout. Take in 20-30g of protein in the 30- to 45-minute period after completing a workout (known as the “recovery window”) when your body is more receptive to fuel. This helps your body to repair the muscles as well as mitigate the effects of stress hormones, which are elevated during exercise. Miss that recovery window and you can often pay the price later, finding yourself reaching for quick sugar fixes and/or less healthy options.

Aside from maximizing that recovery window, as outlined above, athletes should fuel throughout the day with lean proteins, good fats, a wide range of colorful fruits and veggies, and complex carbs (e.g. potatoes, rice, whole grains) during meals and snacks. Hydration around the clock—not just during workouts—is absolutely essential as well. Be sure to sip on water and/or an electrolyte beverage throughout the day.

(Photo: Getty Images)

What do triathletes eat during an Ironman triathlon?

When doing an all-day race like an Ironman, you’re going to need to eat. When training for the race, you’ll have long workouts that will require you to eat while riding your bike or running. There is no one best food for Ironman nutrition—athletes can (and have!) eaten everything from sport nutrition gels to real-food sources. Some even eat peanut butter and jelly sandwiches while riding their bike! 

As you get into a groove with your training, you’ll find you start to discover what you like and dislike when it comes to training foods and fluids. Ask others for their tips and advice, but remember that when it comes to Ironman nutrition, everyone is different and what works for one person can be very different for the next. 

RELATED: Triathlete’s Guide to Race Fueling For Every Distance

As a general rule, however, it’s a good idea to try to take in 1.5 to 2 calories per pound of bodyweight per hour, along with 0.1 to 0.15 fluid ounces of electrolyte drink per hour. And remember that small bites of food and smaller sips of water more frequently are far better than huge calorie intakes all at once. Also be aware that your ability to consume calories will change as the race goes on: It’ll get far harder to eat while running, so be sure to treat the bike as a buffet (of sorts!) for the run. We suggest the following:

Ironman Race Fueling Guidelines
Bike First half: Take on 0.1 to 0.15 fluid ounces of electrolyte drink per pound of bodyweight per hour and 1.5 to 2 calories per pound of bodyweight per hour. It’s important to go for some real food if you can here, such as small salted potatoes, white bread peanut butter and jelly sandwiches. If that sounds impossible, then energy bars or balls are great options too. Second half: Similar to the above, but it might get tougher to stomach solid foods, so move to energy chews or candy if preferred.
Run First half: Aim for 1 to 1.5 calories per pound of bodyweight per hour, with the goal being to keep your blood sugar up. Keep consuming electrolyte drink, drinking to thirst. Second half: It’s highly likely it’ll get harder and harder to keep eating and drinking as the race goes on. Consider moving to energy chews or jelly beans/candy for the last six to eight miles— and you’ll also discover that Coke is the drink of the Gods. If you’re really struggling to get anything down, try sucking on glucose tablets, popping one every five to seven minutes.

As you train, you’ll discover adjustments you need to make—taking in more or fewer calories, alternating between water and sport drinks, or using different electrolyte tablets or powders. This brings us to the golden rule of Ironman race nutrition: Never ever eat anything new on race day. Too many athletes have had their races derailed because they suddenly decided to drink more than their gut could handle, or to eat a new energy bar they bought at the pre-race expo. Set up some key workouts several weeks out from your Ironman race, and do a thorough test of your Ironman nutrition plan, eating and drinking as you plan to on race day. This will give you valuable information and feedback on what works and what doesn’t. 

Our Ask Stacy column, with leading sports nutritionist and exercise physiologist Dr. Stacy Sims, can help you answer a lot of the questions many triathletes have about Ironman fueling plans, the best nutrition for triathletes, how to eat for Ironman training, and much more.

Ask Stacy: How Can I Nail My Recovery Nutrition—and How is This Different for Men and Women?
Ask Stacy: How Much Protein Does a Triathlete Need Every Day?
Ask Stacy: What Makes a Good Pre-Race Meal?
Ask Stacy: Why Am I Always Hungry After Swimming?

You can become an Ironman (yes, you!)

Training for an Ironman isn’t for everyone, but for those who choose to take on the challenge, the experience of training for and racing 140.6 miles can be life-changing. It’s not easy, to be sure. You’ll probably make a mistake or two along the way (we’ve all done it, don’t worry). But you’ll also meet new people, see new places, and achieve something many people would never even try, much less do. When you cross that finish line and hear the announcer proclaim, “YOU are an Ironman!”—well, it’s a pretty spectacular feeling. But don’t take our word for it. Try it for yourself, and send us a selfie with your finisher medal when you do.

How to Train for Ironman
(Photo: Jan Hetfleisch/Getty Images)