Do you suffer with your IronMan Nutrition!
The following article explains how best to tackle an Ironman distance triathlon from a nutritional standpoint. Topics covered are:
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Days before the race
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Hours before the race
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During the race
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Which drinks should I use?
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How much powder do I put in my drinks bottles?
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What types of powder are best?
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How much should I consume?
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Staying in the fat burning zone
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After the race
** The use of pictures of Powerbar products is not a personal endorsement, but merely an illustration of typical products that can be used.**
Eating a diet containing mostly carbohydrates of low glycaemic index along with adequate amounts of essential fats and proteins can ensure that your body will use a greater proportion of fatty acids when exercising, which should lead to better endurance. Ensure that you eat enough fats as reducing fat intake to below 20% of calories can lead to increased use of carbs during exercise and less fat burning.
About 2-3 hours before the race starts it is a good idea to eat some carbohydrate containing foods, preferably a mix of complex carbohydrates with a low glycaemic load and simple carbs with a higher glycaemic load. For an explanation of glycaemic loads:
Example: Porridge with berries and seeds. Wholegrain toast with jam
When you exercise you use up glucose, fats, proteins and salts. During prolonged exercise it is best to replace much of what is lost. This allows the body to continue exercising at the appropriate intensity as well as helping your psychological state.
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Carbohyrate containing drinks with electrolytes are the mainstay of Ironman nutrition. Drinking carbohydrate containing drinks is important for three reasons: a) Water alone is not normally drunk fast enough to ensure adequate hydration due to its bland taste, so a commercial formulation that is easy to consume helps ensure hydration. b) The carbohydrates provide a source of energy which can conserve glycogen levels allowing you to go on exercising for longer. c) The carbohydrates boost blood glucose levels. This has a beneficial effect on mood, maintaining positive focus. |
How much powder do I put in my drinks bottles?
When making up your own drinks for training or racing the usual strength of drinks containing powders is around the 10% solution mark. So in a standard 750ml bottle use 75ml of powder. In the smaller 500ml bottles use 50ml. The powders are often provided with a spoon that contains an exact amount (often 25ml). It is worth hanging onto these once you have one and use it to measure out all future drinks. If the weather is cold and the distance long you may want a stronger solution if you can stomach it as your needs for carbohydrate will be proportionately greater than your needs for water. Conversely if the weather is very hot you may want a slightly more dilute solution, although do not dilute to below 6% as the drink may then become less palatable and you will not drink sufficiently.
What types of powder are best?
Consider the amount of sodium in the drink. If conditions are likely to lead to alot of sweating then it may be best to choose a powder with 0.5-0.7g (21-30mmol) of sodium per 100g of powder. Some powders contain more than this e.g. the powerbar drink available at the Switzerland Ironman, Others such as some SIS drinks contain none at all. Gatorade is about on the mark. It is definitely worth checking.
Look at the tubs to check that the carbohydrates are provided by maltodextrin and fructose in a 2:1 ratio. this maximises the absorption of carbohydrates as compared to a standard maltodextrin only drink.
Some athletes choose to avoid the artificial sweetener, "aspartame - E951" as it has been linked in some studies with an increased risk of cancer, epilepsy and diabetic complications.
During the swim you will be unable to feed and therefore will use up the energy reserves and water that you consumed prior to the race start.
Example for Switzerland Ironman: No nutrition consumed.
On the bike your needs will roughly be 300-400kcals per hour. This is dependent on your size and your work rate. One 750ml sports drink containing 75ml (75g) of powder roughly contains 300kcals. Carbohydrates containing 4kcal per gram.
So dependent on your fluid needs you may need one bottle per hour providing 300kcals and you could then top up with a gel if you needed more calories but no more water. Alternatively make your drink up at 12% concentration giving 360kcals per hour from a 750ml bottle.
Note that your needs for water are unlikely to exceed 1litre per hour. Drinking more than this can put you in danger of hyponatraemia, a state in which your body fluids become too dilute. The condition can be fatal and has caused a number of deaths in marathons and other endurance events over the years. Link to more information:
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Many athletes like to consume some solid food on the bike as an additional way of gaining nutrients. It also provides a focus and something to look forward to. A good time for some solids may be after about 4 hours on the bike, leaving you some time to digest it before the run. Solid foods should be reasonably easy to digest, such as a white roll with ham and cheese. I personally find many bars difficult to consume while exercising, powerbars coming into this category for me. |
Prior to finishing the bike leg it may be worth forcing a little more drink down if you find it difficult drinking on the run. This normally applies more to the fastest in the field than the majority of competitors however.
Example for Switzerland Ironman: One 750ml powerbar sports performance drink per hour. This may well correspond to picking up two bottles per lap. There are three feed stations on each bike lap and so either pick up one 750ml drink from two of them or two 750ml drinks from one of them. Eat a ham and cheese roll (or two) after starting the last of the 3 60k laps.
On the run your needs will roughly be 300-400kcals per hour. It is very difficult to consume solid foods on the run and so you have a choice of combining gels and water or of drinking sports drinks.
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A typical powergel as used in the 2007 Switzerland Ironman contains 41g of which 27g are carbohydrate. This provide 108kcals. As such, one sachet every 20mins should provide the 300+kcals that are required to balance energy needs during an Ironman event. With each sachet aim to drink about 200ml of water. |
Note that some gels are isotonic and that these gels are designed to be consumed without water. The "Go" gels by Science In Sport - SIS come into this category. Modify your water intake appropriately if you are using these.
Link to a table showing items likely to be consumed on race day and their calorific values:
Example for Switzerland Ironman: One gel every 20 minutes. This may well correspond to picking up a gel at every other feed station on the 10k run lap. There are five feed stations on the run route. Try to maintain your drinking rate on the run. This may necessitate stopping periodically. Drink 200ml of fluid per gel. At about the 16k and 32k marks consider drinking a cup of bouillon to maintain your sodium inake. On the last 10k try coca cola or red bull as sugar boost to push you towards the finish.
Staying in the fat-burning zone
By staying in the fat-burning zone (approx <75% max HR*) you conserve more of your glycogen stores for longer although you may use up more of your intra-muscular triglycerides.
Recovery drinks, including protein are a useful way of ensuring that muscles utilised during the race are provided with a source of amino acids that can be used to repair any damaged tissues.