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Ironman training plan: A beginner's guide

With a 2.4-mile swim, 112-mile bike, and a 26.2-mile run, an Ironman triathlon is tough! We explain the basics of tri training: Nutrition, workouts, and training plans.

Written by: Micah Ling

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Ironman triathlon
Photo: Eric Wynn | Slowtwitch

Thinking about taking on an Ironman triathlon? That’s great! There’s a lot (like, a lot) to think about, but if you stick to a training plan, it’ll all come together. The distance alone can be intimidating: a 2.4-mile swim, a 112-mile bike, and a 26.2-mile marathon. Here’s a guide on how to train and things to think about as you prepare.


How long does it take to train for an Ironman?

If you’ve got the time, the ideal training length is six months. If you’ve got some fitness and have been swimming, biking, and running regularly on your own, a 16-week plan is plenty of time.

What is the hardest part of an Ironman?

Depends who you ask, but many will say the mental side. This is an incredible distance, and one of the key ingredients in making it to the finish line is mental strength. So, just like training your body, you’ll want to spend some time thinking about psychology: visualizations, mantras, finding the calm, and being in control of how you react throughout the race.

How should I plan for an Ironman?

If you’re fairly new to triathlon, it’s a smart idea to look into getting a coach who can guide you through all the details of the entire process. If you’ve got some experience in endurance sports and racing, you should still follow a detailed training plan. Full Ironman distance is not something that anyone can “just wing.” Along the way, schedule some tune-up races. Sprint distance, Olympic distance, and 70.3 distance. This will help you prep for the big race, both in terms of the actual swimming, biking, and running, as well as the logistics, fueling, gear, and other details.

Ironman triathlon swimPhoto: Eric Wynn | Slowtwitch


Swimming tends to be most people's weakest link. Sure, you took swimming lessons as a kid, or you swim some laps whenever an overuse running or cycling injury flares up, but long, open-water distances are a totally different game. While this is still the discipline you’ll spend the least amount of time doing during the race, you don’t want to neglect it. When you get well into your training plan, you’ll be swimming at least three times a week, for about an hour each session. If possible, join a local open-water swim club. If you’re going to be racing in the ocean, try to practice there. If you’re going to be in a lake at elevation, try to mimic those conditions.


Yay, biking! This is where the bulk of your training will come in. You’ll ultimately be covering 112 miles of ground on the bike, which is a lot. So you’ll need to spend a lot of time training on the bike. The bike portion is also where you’ll get to load up on fuel — hydration and calories. That takes practice. You not only have to train your legs to get fired up for some long hours, you also have to train your gut.

Ironman triathlon runPhoto: Eric Wynn | Slowtwitch


Most people would call a full marathon a colossal day in and of itself. But for Ironman, it’s the “last leg.” While you’ll want to work up to several long runs, most of your running should come in the form of a “brick workout,” meaning straight off the bike. Running feels different when you come off the bike compared to “just” running. You’ll want to get good and comfortable running on tired legs.

What’s an example Ironman training plan?

A training plan is an important way to consistently increase your training load and adequately (but not too quickly) prepare yourself for an Ironman distance. You also have to practice listening to your body. Not every workout is going to go as planned. If you’ve got a 12-mile run off the bike on your calendar and just feel awful, don’t do it. Maybe substitute a 4-mile easy run, or a swim. Or if you need a day on the couch, do that. It’s easy to put something on paper, but your body will tell you when it needs more or less of something, so listen!

Monday: Rest day

It doesn’t matter which day of the week it is, but dedicate one day to rest. Your muscles need time to recover fully. If you feel like you can’t do absolutely nothing, go for an easy bike ride with little to no climbing, or an easy swim, with no difficult efforts. Or, give your bike a good wash and make sure everything is adjusted, lubed, and in good order.

Tuesday: Bike and run

Brick workouts are the most crucial part of triathlon training. Your race will likely depend on the bike above all, and how well you can run off the bike. You obviously never want to ride 112 miles then run a marathon in training. Save that for race day! But take these brick workouts very seriously. Increase the combined miles slowly. Start with 20 miles on the bike and 2 miles running off the bike with as little down time as possible (maybe even practice your transition once in a while). Eventually, move up in both bike mileage and run mileage. Especially coming off of a rest day, a brick workout should be one of your biggest days of the week.

Wednesday: Swim and cross-train

Think of this as recovery from your brick workout, but also an important time to really focus on the swim. Lots of athletes suffer through the swim, but doing some drills and strengthening your stroke can make a big difference on race day. Don’t just spend time in the water, make it purposeful practice. Also, allow time for stretching and strength training. You don’t need to start bodybuilding, but a good yoga routine with core strengthening can make all the difference and keep you injury-free.

Thursday: Run and swim

When you’re not running off the bike, focus on your form. Add some variety to your routine so that you don’t get bored. If you’re near trails and you do most of your running on pavement, try a trail run. Then head to the pool for a steady-state swim. Go at a pace that you can imagine holding for 2.4 miles.

Friday: Long ride

Think about long ride days as adventures. Take the opportunity to bump up mileage so that you can really get the feel for what race day will be like. Don’t always ride the same route on long days in the saddle. If you’ve got someone who will meet you, go for a point-to-point ride. Also practice your fueling strategy. As you get closer to race day, try to do these rides at the time of day that you’ll be on the bike. Obviously you’ll need to make pit stops along the way, but avoid interruptions as much as possible. Practice eating on the bike.

Saturday: Long run

Similar to the long ride, let this be a day that you really think about fueling. Again, try to start your long run around the time that you’ll start it in the race. Sometimes that’s not possible, but if you always run at 7 a.m. with little to nothing in your stomach, and you won’t be getting to the run portion of the race until 2 p.m., you might be setting your body up for disaster.

Sunday: Swim and run

Another steady-state swim followed by an easy recovery-style run. Think about form and your mental state. Create some mantras and things that you can think about to get you through the times when your body is exhausted. As you get closer to race day, you might start incorporating a day where you do all three disciplines.


Ironman triathlon transition
Photo: Eric Wynn | Slowtwitch

How can I make sure I’m training effectively?

Increase your intensity each month

You don’t want to increase too quickly — trust the process. Just because you feel like you can ride 100 miles in week two of your training doesn’t mean you should. Increasing mileage too quickly will almost always result in injury.

Get a professional bike fit

We can’t emphasize this enough. A great way to avoid injury is to have a professional bike fit. It will make you more efficient on the bike, which will make you faster. It will help preserve your muscles so that you not only have a better ride, but also a better run.

Consider a coach

Especially if you’re new to the sport, a coach is a great idea. As you train, you will start having more and more questions. A good coach will guide you through the whole process will make you more confident and prepared for your big day.

Taper before your race

Sometimes this is the toughest part of training! After you’ve gotten your body used to huge days and lots of exercise, it doesn’t really want to rest. Don’t just lounge around — continue to swim, bike, and run, but at a much lighter load and for shorter durations. Also remember to dedicate lots of time to stretching. A massage is never a bad idea when you’re in your taper.

Track your heart rate

A heart rate monitor is a great way to see how hard you’re working and how well you’re resting. There are a lot of numbers to think about, but being in touch with what your body is doing and how it’s reacting to different levels of intensity is possibly one of the most important stats.


What should I eat while training for Ironman?

Any professional triathlete will quickly tell you that nutrition is the fourth discipline. Hydration and nutrition are things you should be thinking about constantly. Most of the catastrophic issues during a long race or training day come down to improper hydration and lack of calories. That said, everyone is different. You’ll want to experiment with what your gut can handle. In general, if you can take in “real food,” eat more of your solid calories earlier. Bars and other solids early, then switch to gels, chews, and liquid calories later in the race or training ride. Your primary concerns on a long ride should be replenishing carbohydrates and electrolytes. Try to take in 30 to 60 grams of carbohydrates per hour. As usual, listen to your body — you can usually go off of what you crave. Above all, never stop eating and drinking, especially on the ride. If you go for long stretches with no liquids and no calories, you will get into a deficit that will be difficult or impossible to recover from.

Ironman swim startPhoto: Eric Wynn | Slowtwitch

How can I qualify for Ironman Kona?

Each October, the Ironman World Championship event takes place in Kona, Hawaii. It’s considered by many to be the ultimate triathlon experience. So of course, it’s tough to get into. There are four ways to get yourself a start spot in Kona:

  • Earn a slot at one of the Ironman qualifiers held throughout the year
  • Get in through the legacy program (race 12 Ironman events)
  • Win an entry via a lottery
  • Purchase an entry through the Ironman Foundation’s charitable eBay auction

But for most, like the Boston Marathon, qualifying means earning it. Every full-distance Ironman event offers at least one qualifying spot per age group for the world championship.


Ironman distance is a huge undertaking. Some spend years and years preparing. No matter where you are in your journey, remember to take care of yourself. Beyond swimming, biking, and running, there’s also mental strength and the nutrition game. Don’t forget to ask for help. Get a bike fit, hire a coach, find buddies to train with, and enjoy the process!