Competitive Ironman Nutrition Planning
© 2003 by Ultrafit Associates

The following is a suggested guideline for reducing the likelihood of an in-race stomach “shutdown” while eating prior to, during, and immediately following an Ironman-distance race for experienced athletes who are focused on fast times or race placement. If your goal is to finish the race then the pacing instructions here will be too aggressive, but the refueling suggestions may still be effective.
You may need to modify this plan to fit your body size, previous race-nutrition experience, and personal food likes and dislikes. The plan you adopt should be refined starting weeks and months ahead of your Ironman race by experimenting in workouts, especially bricks and long sessions, in C-priority races, and, finally, in B-priority races. Don’t do anything on race day that you have not done successfully many times before.
Determine how many Calories you will take in during the race and the strategy for doing so. As points of reference, an 11- to 12-hour Ironman burns roughly 6,500 to 7,000 Calories and a 9-hour Ironman uses about 8,000 Calories. Approximately half of these Calories come from glycogen (storage form of carbohydrate) and most must be replaced during the race.
Gastric problems are a leading cause of poor performances and DNFs (did not finish) in Ironman-distance races. If your stomach “shuts down” during the race you either 1) went out too fast—poor pacing strategy/control, 2) ate too much solid food, 3) did not take in enough water, 4) ingested too much seawater, or 5) are becoming hyponatremic (low blood sodium level). The following suggested guidelines are intended to prevent these occurrences.
Prior to Race Day
• Reduce food intake as your training volume tapers down (late Peak and Race periods).
• Eat “normal” foods during this period. Do not “experiment.”
Day Before Race
• View the swim course at race time (from water, if possible).
• Eat a large breakfast with an emphasis on moderate to low glycemic index carbohydrate (see list in Triathlete’s Training Bible, page 272 or The Paleo Diet for Athletes).
• Eat a large lunch when next hungry, again emphasizing moderate-low Glycemic Index (GI) foods.
• Have a moderately sized dinner that is “normal” food for you but with limited fiber intake. Soft foods and liquids are best (for example, baked potato). Include mostly moderate- to low-GI foods.
• Stay well hydrated throughout the day but don’t drink beyond your thirst as you may well dilute your electrolyte stores, especially sodium.
• Use extra salt on your food.
Race Day Breakfast
• Take in 800-1500 Calories from moderate to low GI foods 4 to 5 hours prior to the start depending on your size, tolerance for food and experience. This should be rehearsed before bricks and long workouts and before C- and B-priority races.
• For nervous stomach use liquid or semi-solid foods.
• Options may include Ensure, Ultracal, or Boost (approx. 250 Cal/8-ounce can); 1 medium banana (100 Cal); bagel with 1 tablespoon nut butter (250 Cal); 1 cup unsweetened applesauce mixed with 1 ounce protein powder (200 Cal); 1 jar baby food (~100-200 Cal); 1 packet instant oatmeal (~100-200 Cal); 1 cup instant pudding (~100-300 Cal); 1 can tomato soup (200 Cal).
• Example: 4 cans of Ensure, banana, bagel with nut butter (1350 Cal).
• Either go back to bed after breakfast or relax with some light stretching (focus on hips, glutes, and low back).
• Snack but eat no more than 200 Calories/hour in the last 3 hours. Stay with liquid or semi-solid/soft foods that are low on fiber.
• Think calming thoughts or listen to calming music—do not stress yourself out. When apprehensions appear recall previous successes in training and racing.
• 1-1.5 hours before—eat something such as a sports bar and sports drink.
• Eat/drink nothing in the last hour except water (prevents exercise-induced hypoglycemia early in race).
• 10 minutes before—take in as much sports drink as you feel comfortable with.
• Carry a plastic bottle of your sports drink into the water or to your wave start staging area.
• Do not go anaerobic at the start of the swim—hold back.
• Mentally divide the bike portion into fourths. The first quarter is about getting started conservatively; the second quarter is focused on an even, steady pace; the third quarter is when you should gain time if you held back in the first quarter; and the final quarter is a time to ride strongly but steadily. If you went out too fast in quarter 1 you will fade in quarter 3.
• Aim for 300-740 Calories per hour on the bike based on your size, training and racing experience, and tolerance for food intake.
• Carry most of your calories with you on the bike and get water and Gatorade at aid stations.
• Rely more on drinks and less on solid food throughout the race.
• If you have any special nutritional requirements then make sure that you have back-up sources in transition and special needs bags. Start the bike leg with your bike loaded with a little more nutrition than you need for the entire ride.
• Depending on caloric needs and anticipated race duration, carry 2-3, 24oz bottles with about 740 Calories of fluid in each along with gels.
• A 740-Calorie bottle may be made by mixing your favorite sports drink to a normal concentration and then adding Carbo-Pro. Start by mixing your bottles to the normal concentration for the sports drink of your preference. Then add Carbo-Pro (go to to order this). Each scoop (12 ounces) adds 112 Calories. So, for example, using Gatorade Endurance as the base, to each 24-ounce bottle you would add 2 scoops of Gatorade (180 Cal) and 5 scoops of Carbo-Pro (560 Cal). (If you mix this the day before, refrigerate it.)
• Chase each mouthful from the 750-Cal bottle with 2 mouthfuls of water that you get from aid stations and carry on your bike in a frame cage or in a reservoir on your handlebars. By taking in 2 mouthfuls of water per mouthful of refueling mix you are creating an 8.5% solution in your gut. DO NOT USE THE REFUELING MIX WITHOUT THE WATER CHASER.
• If you only use your 750-Cal bottles for refueling and chase each mouthful with 2 mouthfuls of water you can gauge your fluid vs. Calorie intake from the following table. Using a permanent marker to indicate 5-ounce increments on your water bottles will help you to gauge this during the race. Be sure to practice this in training.

Ounces/Hour Calories/Hour
30 308
35 360
40 411
45 462
50 514
55 565
60 617
65 668
70 719

• Take in 300-1000mg of sodium for each hour on the bike from drinks, foods, and supplements. Let heat, humidity, body size, and your experience dictate the amount. Calculate how much sodium is in your drinks, gels, and other foods. Rehearse this in training also.
• If using any solid foods (not recommended if your goal is sub-12 hours), drink only water with them.
• If your experience in racing has been that your mind wanders and you forget to eat and drink, then set your watch to beep every 10-15 minutes as a reminder.
Bike Miles 1-30
• Use your heart rate monitor to prevent excessive effort. Upper zone 1 or mid-zone 2 should be right for this quarter depending on what your training experience has been. Avoid “racing” with others—pay attention to your own race. Going too hard now may have disastrous consequences later on.
• This should feel like the slowest part of the bike leg, relative to terrain and wind. Do not hammer out of T1. Hold back. The heart rate zone readings should be the lowest of the four portions of the bike leg. You should be passed by lots of other athletes now. If not, you’re going too fast. Everyone who passes you now will come back starting after mile 61.
• Pacing is key to nutritional success early in the race. Keep your heart rate down. Set your heart rate monitor to beep at the bottom of your 3 zone. You should not hear the beep for the first 30 miles on the bike. If you do, you are going too hard and the chances of digestive problems later on are rising.
• Drink water before starting any calories. Begin sipping right away out of T1 and continue for 20 minutes. Start liquid refueling after 20 minutes.
Bike Miles 31-60
• The goal of the second quarter is to maintain a steady effort at goal ironman-distance bike pace.
• Ride steadily and predominantly in the mid- to upper 2 zone. Remember that only the fittest athletes, generally elites with very fast bike portions, will be able to tolerate sustained periods of 3 zone riding. You would be well advised to ride under the intensity of your toughest race simulation rides.
Bike Miles 61-90
• If you are feeling good, consider increasing the speed/effort, but only slightly. This is where you can move up through the field.
• You may be experiencing cardiac drift by now, so pay close attention to how you feel and less to your heart rate monitor. Stay focused.
• You should have to pee during this portion. If not, you are not drinking enough.
• Regardless of the cause, you should slow down immediately when faced with stomach issues regardless of your time or pacing goals. The time that you “lose” will be more that made up with an improved run split. Pushing through stomach issues doesn’t work.
Bike Miles 91-112
• Continue to eat although you may not feel like it.
• Effort should feel like zone 2—steady to moderately hard—regardless of what your heart rate monitor says.
• Gauge your effort based on how you feel, not heart rate or pace. Use these as secondary markers of intensity, if used at all.
• Divide the run into three parts. Part 1 has to do with finding a comfortable pace/effort. Part 2 is a time to run steadily and cautiously. Part 3 is the time to push your pacing limits if you feel like it.
Run Minutes 1-20
• Run easily the first 20 minutes getting in as many liquid calories as possible – aim for at least 200 calories during this time based on your training and previous race experience.
Run 21 Minutes to Mile 18
• Resist the temptation to pick up the pace. Save it for the last 8 miles.
• Take in gel water, or Gatorade, or Coke at every aid station (do not take gels with Gatorade).
• When using gels, immediately take in at least 6oz water for each packet to avoid dehydration.
• Get in at least 200 Calories per hour—more if possible and you’ve practiced eating at a higher rate in run training of up to 400-500 Calories per hour (200 Cal is 2 gels or 8oz Coke or 24oz Gatorade).
Run Mile 18 to Finish
• If you’ve come to mile 18 feeling good and you can pick up the pace, you will gain a lot of time on your competition who went out too fast. Smart pacing and refueling prior to mile 18 will pay off now.
• Continue to take in sports drinks or gels with water (6oz minimum per packet of gel).
Immediate Post-Race
• Remove all heat stress as soon as possible.
• Continue moving around for 5-10 minutes after crossing the finish line.
• Begin drinking fluids, especially those with sodium, carbohydrate, and protein.
• Eat any foods that appeal to you but avoid fiber and spicy foods.
• Eat and drink as much as you feel like taking in.
• Do not drink water only as this may exacerbate hyponatremia.

Parting Thoughts
From Scott Molina, legendary triathlete: "When you feel good, eat." (Translation: When you feel good during the race don’t hammer; rather, take advantage of this time to get more fuel onboard.)
Another thought from Ryan Bolton, winner of Ironman USA: “When your attitude about the race changes, take in some fuel.” (Translation: Feeling sorry for yourself or angry at the wind (or whatever) is potentially a sign of low blood sugar. Eat.)