How Triathlon Training Nutrition Works

By: Meghan E. Smith
Whether you're running a sprint triathlon or a testing the limits in an Ironman event, nutrition is an important part of the training process.

Deciding to run a triathlon, whether it's the sprint version or a full-fledged Ironman, is a major commitment. Preparing for the event means long hours of running, swimming and biking, plus additional strength and core training. Triathletes also need to practice transitioning smoothly from one leg of the race to another -- something that's a lot harder than you'd think.

But perhaps the most crucial element of any triathlon training regimen is your nutrition plan. Making sure your body gets the right combination of carbohydrates, protein, vitamins and hydration can mean the difference between a successful race and a painful ordeal. This combination isn't going to be the same for every person; all of our bodies burn energy at different rates in slightly different ways. Accordingly, one of the most important parts of your training will be to discern how much fuel your body will need, and when it will need it.


Sprint Triathlon Nutrition

Water will help absorb important nutrients you need during the training process.

Sprint triathlons are where most novice triathletes get their feet wet. It's a good place to start if you're trying to decide whether to tackle any of the more rigorous triathlon events. Though the distances involved may vary from one sprint triathlon to the next, the average event might break down as follows:

  • a 400-meter swim (.25 miles)
  • a 20-kilometer bike ride (12 miles)
  • a 5-kilometer run (3.1 miles)

When you add in transition times, you might be looking at almost two hours for the entire event [source: Sprint Triathlon]. Keeping your body energized and hydrated throughout can be a challenge.


Since many sprint triathletes are just getting used to a multi-leg sporting event, it's important to consider how your body reacts differently to each individual event, as well as how it handles the triathlon as a whole. Experiment with different foods to see what your stomach can tolerate during a high-intensity workout. There are lots of options out there, including sports beans, blocks (which have a chewy consistency), gels and drinks. You can eat all of these on the go, and they'll give your body the combination of carbohydrates, protein and vitamins it needs to keep going throughout the event. Make sure you drink plenty of water along with the snacks; it helps your body absorb the essential nutrients and prevents stomach irritation.

Is the sprint triathlon not enough of a challenge for you? See the next page for a feat of Olympic proportions.


Olympic Triathlon Nutrition

Fruits are a good source of carbs for triathletes.

As one might guess from the name, an Olympic Triathlon is the one in which athletes compete every four years at the Summer Olympic Games. You don't have to be an Olympic athlete to take part in this event; Olympic triathlons are held regularly all over the world, outside the context of the Olympic Games.

Here are the distances involved:


  • a 1.5-kilometer swim (.93 miles)
  • a 40-kilometer bike ride (24.8 miles)
  • a 10-kilometer run (6.2 miles)

So, the distances for the cycling and running sections are about double what they are in the sprint triathlon, while the swim is around three times longer [source:]. With that in mind, let's focus on what you need to eat in order to make it through a tough swim.

"Carbo-loading" is a popular term among sports aficionados, but what kind of carbs should you be loading? Instead of traditional carbohydrate vehicles like pasta and bread, USA Swimming advises swimmers to get their carbs from fruit. Fruit contains natural sugars, as well as much-needed vitamins and minerals. As a bonus, fruits like blueberries are an excellent source of antioxidants, which help cleanse your body of the free radicals produced during an intense workout. Left unchecked, free radicals can break down muscle tissue, so getting those out of your system is crucial [source:]. Also, instead of consuming the traditional three large meals a day, stick to a smaller meal every two or three hours. This will help keep your energy levels steady and prevent a major crash that comes with falling blood sugar [source:].

So, you've got a handle on swimming -- let's take a look at some other key nutritional tips.


Half-Ironman Nutrition

Although hydration is clearly important, drinking too much can make you sick.

Next on the triathlon ladder is the Half-Ironman, officially known as Ironman70.3. There are a number of races that may cover the same distances as the Ironman70.3 or the full Ironman events, but unless they're officially sponsored by the Ironman Organization, participants usually refer to them as half- or full-distance triathlons. The Half-Ironman distances break down as follows:

  • a 1.9-kilometer swim (1.2 miles)
  • a 90-kilometer bike ride (56 miles)
  • a 21-kilometer run (13.1 miles)

Since the Ironman70.3 bumps the cycling leg up to 56 miles, let's focus on that. The cycling part of any triathlon offers a major benefit, in that it's the easiest of the three legs in which to grab your necessary food and hydration. Staying away from dehydration is crucial, so you should probably drink as much water as possible, right?


Not so. As important as it is to stay hydrated, becoming over-hydrated can lead to a problem called Exercise-Associated Hyponatremia (EAH). EAH means that your blood's sodium level is abnormally low. It can occur in cases where athletes drink far too much water at one time, thereby flooding the body with more than it can process. But EAH can also occur in instances where the body is retaining even moderate amounts of excess water, instead of releasing it through perspiration or urination. The effects EAH can have on your body are numerous, and sometimes quite serious, so pay attention to the symptoms. Weigh yourself before and after your workout; if you've gained weight, that's a warning sign. Feeling bloated is another indication that something's awry, as are indentations left by your waistband or socks. At the first sign of overhydration, call your doctor [source:].

Got your fluids under control? See the next page to learn about the most iconic triathlon out there.


Ironman Nutrition

Blueberries are an excellent source of antioxidants.

For the most hardcore triathletes out there, the classic demonstration of endurance is the Ironman. At 140.6 miles, it's an incredible test of your body's limits. The individual leg-lengths are as follows:

  • a 3.9-kilometer swim (2.4 miles)
  • a 180-kilometer bike ride (112 miles)
  • a 42-kilometer run (26.2 miles)

In addition to biking for more than 100 miles and swimming nearly two and a half, you're running an entire marathon. To the uninitiated triathlete, it might seem impossible. But with the right training and dedication, even this incredible feat is within your reach.


The nutrition tips for swimming and cycling also hold true for a marathon-length race. You'll need to help yourself out during the increased distances of all the events, so be prepared to refuel on the go and during transitions.

Just as important as observing proper nutrition before and during the event is helping your body recover afterward. No matter how in shape you are, competing in an Ironman triathlon is going to leave you essentially running on empty. Between 15 and 30 minutes after you've completed the race, you should start replacing the fluids your body lost. This means 20 to 24 ounces of fluid for each pound lost during the race. You'll also need to replace sodium -- about 450 milligrams of sodium per 24 ounces of fluid. Make sure you don't guzzle your fluids. Reclaim that hydration at a slow and steady pace. Avoid caffeine and alcohol, since they'll make dehydration worse. You'll also want to take in about 50 to 75 grams of carbohydrates and 6 to 20 grams of protein within 15 to 30 minutes after the finish, and repeat that every two hours. This will help stabilize your blood sugar and repair your muscles. If you're feeling nauseous, stick with liquids at first, and then start in on small bites of solid food once your stomach settles [source:].

Ready to take the plunge? See the next page for lots more information about staying healthy while training for a triathlon.


Lots More Information

Related Articles

  • Coffman, John. "Workout Nutrition." (Sept. 9, 2010)
  • Hoefs, Jeremy. "20-Week Sprint Triathlon Training." April 30, 2010. (Sept. 7, 2010)
  • Hutchison, Jennifer. "Post Ironman Nutrition." Nov. 9, 2005. (Sept. 11, 2010)
  • "How long does it take to complete a sprint triathlon?" Sept. 16, 2009. (Sept. 8, 2010)
  • USA Swimming. "Fueling Your Stroke." (Sept. 9, 2010)>
  • Weschler, Lulu. "Drinking Too Much." (Sept. 8, 2010)