Wednesday, February 3, 2016

Ironman Race Nutrition

Competitive Ironman Nutrition Planning

© 2003 by Ultrafit Associates
[With Edit/Update by Gordo in December 2008]

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.

My best advice is contained in the Second Edition of Going Long.

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 could burn up to 7,000 calories and a 9-hour Ironman could use up to 8,000 calories.

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 then you very likely went out too fast.

Other contributing factors can be: too much solid food; a lack of fluid; or excessive fluid. The following is 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.
  • Eat a large lunch when next hungry, again emphasizing moderate-low GI foods.
  • Have a moderately sized dinner that is "normal" food for you but with limited fiber intake. Moderate to low GI foods.
  • Stay well hydrated throughout the day.
  • Use extra salt on food.

Race Day Breakfast

  • Take in 1000-1500 Calories from moderate to low glycemic index foods 3 to 4 hours prior to the start. 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 foods.
  • 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-drink something such as a 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 (don't go crazy with it!).


  • Take full, relaxed breaths as you wait for the swim start.
  • Do not go anaerobic at the start of the swim-hold back.


  • Mentally divide the bike portion into fourths. The first quarter is about fueling for the day; 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.
  • Aim for 200-600 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 sports drink at aid stations.
  • Rely more on drinks and less on solid food as the race progresses.
  • 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, 20oz bottles.
  • A 750-calorie bottle may be made by mixing your favorite sports drink to a normal concentration and then adding sports drink powder. Drinks containing protein should be mixed race morning.
  • Chase each mouthful from the 750-Cal bottle with 2 to 3 mouthfuls of water that you get from aid stations.
  • Take in as much as 1,000mg of sodium for each hour on the bike from drinks, foods, and supplements. Let heat, humidity, body size, and your experience dictate the amount.
  • If using any solid foods (not recommended), 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 15 minutes as a reminder.

Bike Miles 1-30

  • Use your heart rate monitor to prevent excessive effort. Relax and settle your heart rate down -- MANY people will pass you, you will be seeing most of them again in three to six hours! Avoid "racing" with others-pay attention to your own race. Going too hard now will 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.
  • 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 far too hard and chances of digestive problems are high.
  • Drink water before starting any calories. Begin sipping right away out of T1 and continue for 20 minutes. Start liquid feedings 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 in line with your race simulation workouts. 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 then stay aero, relax and have something to eat/drink. You still have a long way to go. At this stage, you will start to move up through the field.
  • 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.


  • Walk through T2 and relax at the beginning of the marathon. You have a long way to go and need to settle into a smooth cadence. To run well, the first 5K of your marathon needs to be the slowest section of your run.
  • 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 very easily the first 20 minutes getting in as liquid calories - 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 Sports Drink, 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 - 200 Cal is 2 gels or 16oz of cola or sports drink.

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.)

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