Fueling an Ironman race

You just spent the better part of a year training for an Ironman race.  Did you remember to train the fourth discipline of triathlon, fueling?

The key to a proper fueling strategy is practice, practice, and practice in training and racing in all weather conditions.

Signs of improper fueling include: inability to hold power on the bike, a drop in heart rate, or the inability to run at your prescribed heartrate or pace, feeling like you are starving after exercise, and a negative attitude. Don’t let inadequate fueling during your Ironman derail your race and all of the hard work and money that you have invested in your race.

Read the Athlete’s Guide to find out what nutrition is offered on the course. It’s better if you can use some of this nutrition rather than pack it all onto your bike and run gear. Also, have a plan in case something happens to the nutrition that you are carrying. You could have extra in your Special Needs bag or know what you can take from the course if something should happen to all of your nutrition.

The table below can be used as a guide for determining your personal best nutrition plan for race day. Practice and tweak this plan the in months and weeks before your race.

Event Nutrition Scheme
Prior to Race Day Reduce food as you taper.   Maintain your normal diet.
Day Before the Race Eat a normal diet, but limit fiber intake. Eat a large breakfast, large lunch and a moderately sized dinner of foods normal to you. Limit acidic foods at dinner (ex. Marinara sauce).
Race-Day Breakfast Eat a substantial breakfast (800 – 1,500 calories) of food that you have rehearsed in training and other races.   Try to pick foods with moderate to low- glycemic index. If you have a nervous stomach then you may want to stick with semi solid foods. Give yourself plenty of time to digest this before the race, ~3hrs.
Pre-Race Some like a snack of sports bar and with a sports drink 1-1.5hr before the race and then take on sports drink 10min before the race. I personally take on a gel and some water 15min before the race. In the last few hours before the race, try to keep the calories down to no more than 200/hr.
Bike Aim for 300-500 calories per hour depending on size, training, how hard you are racing, and food tolerance.   Also, make sure you are taking in enough sodium per hour. Start out with 500mg/hr and adjust up or down as needed. This should be based on what you have rehearsed in training and racing. I prefer solid foods on the bike, but I switch to semi solids and liquids around mile 80 so that it can be digested. If you can’t do solid foods or need additional calories, then add Maltodextrine (Carbo Pro) to your sports drink. Mark off the bottle in thirds with a sharpie and take on one third of the bottle every hour. I mix Gatorade and Malto for 344cal per bottle to give me additional calories.   I put something in my mouth every 15minutes. Use the bike as your opportunity to eat.
Run Take on something at every aid station (gel and water, coke, chicken broth, or sports drink). I go based on feel, but try to stick with Power Bar gels and water and then start taking Coke on the second half of the marathon if I need it. Coke can be addictive and can make you perk up, but you pretty much have to take it every mile once you start; use with caution.


My personal pre Ironman breakfast:

1Bagel (260cal) with 2tbsp peanut butter (190cal) + 1banana (180cal) + Froot Loops 1cup (110cal) + 2cups of coffee with Coffee Mate French Vanilla Creamer (180cal) + Gatorade (80cal) = 1,000cal

Other example Breakfast choices:

1 Banana (180cal) + 1Bagel (260cal) with 2tbsp Peanut Butter (190cal) + Ensure (250cal) = 880cal

1 cup apple sauce (200cal), Protein powder Beverly International UMP (120cal), 1 pack instant oatmeal (100cal) with 2tbsp Peanut Butter (190cal) + Instant pudding (150cal) + 1 bottle Gatorade (120)= 880cal

Other foods could include jar of baby food (100-200cal), 2 pastry Pop Tarts (400cal), sweet potatoes (100cal), 1 can tomato soup (200cal).

My Personal Nutrition on the Bike:

If temps are 80 degrees or below then I’ll add chocolate bars to my bento box if it’s warmer then I add Payday bars. I need something tasty that I actually want to eat, I tend to under eat if I don’t have that.

1 Snickers bar = 410cal and 180mg of sodium (cut up into 4 pieces for ~100cal units)

5 pieces of Take Five (per piece) = 105cal and 95mg sodium

2 Payday candy bars (per bar) = 240cal and 120mg sodium (divided into halves 120cal each)

Clif Shot Blocks= 100cal and 50-150mg sodium, 20mg potassium

1 Clif Bar = 260cal, 240mg sodium, and 180mg of potassium (divided up into quarters for 65cal)

2 Bottles Marked into thirds containing Gatorade + Malto (1/4c per bottle) = 115cal per mark each hour

This is divided up for 300cal per hour with calories taken on every 15 min. I start by alternating pieces of chocolate bar (or Payday), Clif Bar, Clif Blocks, and electrolyte drink mix. At Mile 80 I switch to just my electrolyte drink and Clif Blocks.

Other example solid food for the bike:

Fig Newtons= 1 cookie 100cal, 95mg sodium, and 70mg potassium

Power Bar Energy Blasts= 200cal and 30mg sodium

Rold Gold pretzel thins (9 pretzels) = 110cal and 490mg sodium

Honey Stinger Waffles = 160cal and 80mg sodium

Clif Bar = 260cal, 240mg sodium, and 180mg of potassium

Non-solid fuel

Power Bar gel = 110cal and 200mg sodium and 20mg potassium

Honey Stinger gel= 100cal, 50mg sodium, and 85mg potassium

GU gel= 100cal, 60mg sodium, and 40mg potassium

GU Roctane gel= 100cal, 125mg sodium, 55mg potassium, and 35mg calcium

Gatorade per 12oz serving = 80cal 160mg sodium, and 45mg potassium

Gatorade Perform per bottle (on the course) = 180cal, 300mg sodium, and 80mg potassium

CarboPro (Maltodextrine) = 224cal per 1/4cup

Salt Sticks™ (1 pill)= 215 mg sodium, 63 mg potassium, 22 mg calcium, 11 mg magnesium, 100 IU Vitamin D (Buffered for digestion and absorption)


-“When you feel good, don’t hammer, take the opportunity to eat” Scott Molina

Have a great race!! If you have any questions about fueling during your Ironman race, then send me a message.