Thinking of Joining USA Triathlon?

Be a part of our 550,000 member community of multisport athletes. Membership benefits include a subscription to the quarterly USA Triathlon magazine, discounts from USA Triathlon partners, inclusion in the national rankings, excess accident insurance at events, and savings at races. To see why you should join or renew today, visit the membership benefits page. Already a member? Login below.

Forgot Password  |  Forgot Member ID  |  Help Renew Membership Become a Member

Top Tips for Long-Distance Racing

By Monique Ryan

Nutritional preparation for Ironman racing is both a science and an art, with each competitor formulating their own mix of training and race nutrition strategies. However, there are some essential ingredients to race-day success. Below are some nutrition tips deserving of your time and attention in preparation for race day.

Your Daily Diet

Of course the quality of your daily diet is important for your health, with whole grains, fruit, and vegetables comprising the majority of your carbohydrate intake. Lean proteins, and adequate amounts of healthy fat also provide dietary balance. But much of what distinguishes your training diet and affects your recovery is how you portion and time your food intake.

Match your nutrition plan to your training plan

Often referred to as nutritional periodization, this simply requires that you eat just the right amounts of carbohydrate, protein, and fat for that day’s training. You can have the best nutrition on race day, but if you do not feed your body appropriately every day, you will not arrive at the race in the best shape possible.

Long training days and intense training sessions mean that you burn through more muscle glycogen for fuel, and underconsuming carbohydrate can compromise muscle glycogen recovery. Your body also needs plenty of protein when you are building your training program for muscle tissue repair and a strong immune system. Super long cycling days may require that you take your fat intake up a notch.

Each Ironman competitor has his or her own training-specific nutritional requirements. But don’t underestimate the amount of food that you require for good recovery during IM training. On specific training days you may require anywhere from 3,500 to 4,500 calories daily. 

Practice Recovery Nutrition

In addition to meeting your total nutritional requirements for the day, make sure that you practice recovery nutrition between training sessions. IM triathletes are in a constant state of refueling from long, intense, and multiple training sessions. Immediate recovery nutrition starts the important refueling process and is especially important if you have less than eight hours recovery time before the next training session, and crucial if you have only four hours recovery time.

Make sure that you have a recovery snack or meal providing 1.5 gram carbohydrate per kilogram of body weight, 10-15 grams of protein, and fluids and sodium to start the rehydration process. Eating and drinking every two to three hours steadily supplies your body with the nutrients to refuel and rehydrate. Triathletes often eat five to six times daily to support not only their recovery needs, but also to obtain a steady supply of fuel throughout the day and before training, without overeating in the hours before training.

Training Nutrition

Much of Ironman training is high volume and plenty of it as you prepare for this ultra-endurance event. Because your muscle and liver glycogen stores can run low during long and hard training sessions,  what you consume during training is essential to quality workouts. 
Experiment with nutrition in training and be willing to try new strategies

Training is the most optimal time to experiment with nutrition strategies for refueling and hydrating for race day. Ironman competitors are constantly trying to find that delicate balance of fuel, fluid, and electrolytes that both go down smoothly and that stay down. Often race day fuel needs can exceed your stomach’s capacity and intestinal tolerances. Experiment to find your favorite sports drinks, gels, bars, and electrolyte supplements, and learn about the products offered on the race course. Several weeks before race day have a plan for T1, the bike, your special needs bag, T2 and the run in regards to the amounts your should consume at specific intervals. Experimentation is especially important during long training rides that are followed by a transition run. But keep in mind that whatever your tolerances on this type of training day, you bike ride is followed by a marathon, so plan accordingly. 

Consume a training nutrition mix of multiple carbohydrate sources

Research from the University of Birmingham in England indicates that doubling or tripling up on your carbohydrate sources can push your gut tolerance beyond the previously measured limit of 1 gram per minute (about 60 g per hour), and maximize your fuel absorption. Common carbohydrate sources in sports nutrition products are glucose, glucose chains (often maltodextrin), fructose, and sucrose, which use a variety of transporters to cross the small intestine, after which they enter your bloodstream and provide fuel. 

Two studies found that a glucose/fructose mix or a glucose sucrose mix allowed study subjects to absorb and burn carbohydrate at a rate of 1.8 grams per minute (108 g per hour) while cycling. Notes researcher Roy Jentjens, PhD, “The finding from our laboratory suggest that to get a high rate of carbohydrate oxidation, a mixture of glucose and fructose at 1.8 grams per minute may be the preferred combination. One study that looked performance results found that combinations of glucose + fructose and maltodextrin + fructose resulted in greater fuel delivery, reduced fatigue and better performance when ingested at a rate of about 90 grams per hour. When compared to a glucose drink, these carbohydrate mixtures have also been associated with faster stomach emptying and fluid delivery.


After all your practice and experimentation in training, much of your success on race day comes down to the nutritional strategies that work best for your tolerances and energy requirements. 

Develop a race nutrition plan and schedule for the bike, run and transitions

After plenty of practice and experimentation, you should develop a race nutrition plan several weeks before the race. Plan ahead and know how many bottles to prepare for the bike, what to put in your special needs bag and what products you would like to use that are offered on the course. Many seasoned Ironman competitors advise to always pack a little extra, better to have some choices of bars and gels, than to fall short of what you need. 

During all your planning, bear in mind the rules of gastric emptying

The more concentrated the mix, the slower it empties from your stomach. And all semi-solid and solid food should be consumed with water. As the race progresses you are less likely to be hydrated and your stomach will become more sensitive, especially on the run. Changing flavors and variety can help during your 140-plus mile picnic. 

Carbo-load and hydrate optimally in the 48 to 72 hours before the race

During the race taper, consider that you are resting your muscles and building important glycogen fuel stores. Aim for eight to nine grams of carbohydrate for every kilogram of body weight. Your calorie needs may be lower to due limited workouts, often requiring that much of your diet be derived from carbohydrate. Stick with safe and easy to digest foods, nothing unusual or questionable. Determine your own tolerances.

Optimal hydration is also important

Urine should be light in color, and take care to not overhydrate and increase your risk for hyponatremia or lowered blood sodium levels during the race. Make sure that you consume some good sodium sources and added salt in the days leading up to the race, especially if you are a salty sweater.

Dial in your race morning meal

The pre-race meal is the nutritional start of your day and it should leave you feeling physiologically comfortable and psychologically satisfied. Many competitors have some easy to digest solid foods, along with a good nutritional punch from liquid foods.

Summary Tips

Eat a quality diet but food portions and timing should match your training for optimal daily recovery, and for weekly recovery throughout your training program.

Experiment in training with sports drinks and other supplements to develop a race nutrition plan. What goes down and stays down, fuels and hydrates your body. Don’t overfuel or you will develop gastrointestinal problems.

In the days leading up to the race, eat enough carbohydrate to load your muscles with glycogen and optimally hydrate. Stick with safe and simple foods and sports nutrition supplement the day before the race and have a pre-race meal that favors liquid carbohydrate sources.

Monique Ryan, MS, RD is the author of Sports Nutrition for Endurance Athletes, 2nd edition (VeloPress 2007). Click here to view more about the book or purchase. She was a member of the Athens 2004 Performance Enhancement Teams for USA Triathlon and USA Cycling Women’s Road Team. She is owner of Personal Nutrition Designs and offers her sports nutrition “E Program” at