Ironman Triathlon

About Ironman Triathlon

Ironman triathlon is a gruelling event consisting of a 3.8km swim, followed by a 180km ride, topped off with a 42.2km run. Time taken to complete races vary from winning times in males (8.5-9hrs) and females around 9.5+ hours. The average completion time is around 11-12hrs (males) and cut off times for completion range from 15.5hrs - 17hrs. The events usually start at approximately 6-6.30am and competitors will finish from anytime after 4pm that same day. TIP: Pre-race check in can take up to 1hr \ be prepared to be there early.

Who competes in Ironman Triathlons?

In general experienced triathletes with a long training history compete, as many years of training are required to undertake an event of this duration. The biggest age group is 30-40years, but don't be surprised to see athletes in their 50's and 60's. Ironman competitors often need to complete specified half ironman races and place high enough in their age group to earn a coveted ironman spot.

Training Diet & Fluid Needs

The purpose of this information is to address competition issues rather than training dietary issues. For training diet information including discussion on fluid requirements, refer to Triathlon fact sheet.

What Should I Eat Pre-Event?

The days before:

Take familiar foods when competing in different or unfamiliar locations eg pasta, pasta sauce, bread, cereal/muesli bars, spreads eg jam, peanut butter, vegemite, cordial, meal replacers,
Look for accommodation with cooking facilities to maintain some familiarity with foods, particularly in the pre-race period.
Carbohydrate loading 2-3 days prior to race. Refer to the fact sheet Eating and Drinking Before Sport
Many ironman races have a pre-race Carbohydrate Loading dinner 1-2 nights before the race, however be aware of the fat content of some of the meals offered. Remember it is carbohydrate loading not fat loading!
There are specialised Carbohydrate loader drinks (eg PB Carbo loader) and meal substitutes (eg Sustagen sport) that can help to achieve the 10g of carbohydrate per kg body weight required to maximise muscle glycogen levels. Other compact sources of carbohydrate such as cereal and sports bars may be useful additions to usual food intake to get the extra carbohydrate in.
Starting the event well hydrated is a priority. Having a drinking plan for the 24-36 hours to ensure you are well hydrated is a good strategy. Supplements such as Glycerol can be used with fluid intake to get to a state of "hyperhydration" where extra fluid can be stored.[Tip: As with any supplement trialling glycerol during training is recommended before trying on race day as there is a high rate of poor tolerance]
Make a fluid intake plan based on training experiences.
Prepare bidons, gels etc with race bag as part of race strategy.
Pack suitable snacks into separate bike transition and run transition bags. Usually these bags are checked in the day before the race, so must not include perishable items. Perishable items can be checked into a "special needs bag" on the morning of a race and will be available only from designated aid stations. Check the race rules for more information.
Check out what's available through race directors to plan ahead if possible.
On race day ensure you get up and eat at least 2 hours prior to the race to allow food to empty from the stomach
Be familiar with the race foods you intend to use. Don't try new things on race day!

A Sports Dietitian can advise you on a low residue diet if "the trots" or more formally, "runners diarrhoea" are a problem during a race!

What Should I Eat/Drink During Competition?

Swim

The swim leg can take up to 2 hours and there is no way of eating or drinking while swimming other than what you take by accident!
Therefore drink up to 500ml in the half hour prior to the start.
At transition drink sports drink. This will help replenish fluid and carbohydrate and get rid of the salt water taste in the mouth. There will be plenty of opportunity during the bike leg to eat, so it is not an immediate priority during transition.

Ride

Plan to get 1-1.2g Carbohydrate per kg body weight per hour of race. Therefore if you weigh 70 kg then try to get in 70-84g carbohydrate per hour. This can be in the form of food and fluids.
Try to stick to a race strategy with a mix of gels, bars, snacks and drinks to meet carbohydrate and salt needs and avoid "flavour fatigue". Be prepared to have some back up plans though.
Know your fluid requirements and drink to fluid plan. Fluids in Sport
Start the bike leg with a good supply of sports foods and gels to get through to the aid stations. In case you miss the aid station some triathletes carry a "bento" box or empty bidons to store their supplies.
Be prepared for the aid stations and know where they are. Pre-race information should tell you what is available at aid stations and how far apart these are. Generally aid stations are between 10-20kms apart depending on the bike course.
If you have special needs these should be pre-organised with the race organisers (see "the days before" above).
There is no need to carry everything you need for the race duration as the extra weight can slow you down, but it is wise to have a back up plan in the case the aid stations do not have everything you need or you miss an aid station.
As you approach the aid stations, know what you want and yell it out as you come through. Know the order of foods and fluids as these may be spread out over the aid station.
Consider foods that are easy to chew given that race intensity will be high.
Consider race foods and how easy they are to open while riding. For example very liquid gels can spill easily, bars may be easier to manage if cut up into pieces pre-race.
Using the timer on your watch can help you to remember to eat and drink at regular intervals along the way.
As you get towards the end of the ride leg try to get extra fluids in. Taking fluids on the bike is easier than during the run leg, so plan to start the run leg well hydrated.
Be aware there are race rules about toilet stops. There should be toilet stations available.

Run

Use foods you know you can tolerate while running.
Take time through aid stations. Walking through can avoid drink spillage allowing extra fluid to be taken, with the advantage reaped later by being better hydrated.
Not all aid stations will be the same so know which ones have the products you'll be looking for. Check for different fruits and foods like vegemite sandwiches, soups etc to avoid flavour fatigue.
There will be times when fuel belts to carry extra gels and bars can be helpful.
Salt tablets can be helpful to maintain salt intakes and aid fluid retention in athletes prone to heavy sweating and cramping. Salt tablets should be taken with fluids but remember to wrap them or keep in a waterproof pouch attached to fuel belt to avoid them dissolving before you get a chance to take them.
Caffeine in various forms is a favourite of ultra endurance athletes late in events for its stimulant properties. Small doses such as those found in a can of cola soft drink can be enough to improve performance. Degassed cola drinks are available at designated aid stations in many ironman races. Plan when you think you'll need to take it for maximum effect.

What About Recovery?

Refuelling and rehydrating after an event such as ironman is important, however most competitors will take a few weeks break from training after an ironman race. Immediate recovery nutrition issues including replacement of carbohydrate, electrolytes and fluids are covered in the Eating and Drinking After Sport fact sheet (insert hyperlink). Longer term recovery issues are a lower priority due to the significant reduction in training load post-race, so ironman finishers can reward themselves with a few treat foods that may have been restricted during training over the next few days and weeks.
Avoid alcohol until fully re-hydrated.

Other Nutrition Tips

Always consider food safety issues, ask for advice with regards to the safety of local foods and water supplies if travelling overseas. Buying bottled water is often the safest option.

How to get involved

Contact Triathlon Australia or visit

Click here to download Ironman Triathlon fact sheet (61KB)

Authors: Members of Sports Dietitians Australia, South Australia

A very special thanks to Verity Pietsch, Elite female ironman triathlete for her assistance and SDA Member Alison Caiafa.