Ironman Nutrition: An Individualized Approach

The Ironman triathlon is a grueling race consisting of three events: a 2.4 mile swim, a 112 mile bike leg and a 26.2 mile run leg. To prepare for this race, one needs to combine sport specific training, recovery, time management and nutrition. While it may be difficult to quantify the importance of each, without proper race day nutrition, your chances for success dwindle. There is some good scientific evidence on what your body goes through nutritionally during an ironman. This serves as the foundation for your nutrition plan during an Ironman. However, our bodies are unique and we react to food differently; caloric intake will differ as well as the type of calories consumed. It is on this level that an athlete must fine tune the program to fit his or her needs. This is accomplished through practice and trial and error.

In triathlon’s infancy, there was very little written about nutrition in relationship to Ironman triathlon (Carlson, 2002). At that time in sports nutrition, most studies focused on 2-4 hour running events like the marathon. There was nothing available to determine the needs of 12-17 hour endurance contests (Carlson, 2002). Ironman triathletes only had the professional ranks’ anecdotal stories of what was used on training rides and during events. One of the first drinks was defizzed coke with aspirin and No-Doz. Competitors would eat Twinkies, bananas and figs; they drank beer, chocolate milk and other concoctions (Carlson, 2002).

Triathletes have since evolved from these days. From this experimentation in the early days, companies sprouted to give athletes products that could help with nutrition during the race, e.g. Power Bar, Cliff Bar, Hammer Nutrition (Carlson, 2002). Nutritional companies have jumped on the bandwagon and now there are a bunch of “scientifically” proven products ranging from gels and bars to drinks and tablets, all to help the athlete reach his goal. More and more studies are defining what endurance athletes need to get them to the finish line.

Kimber, Ross, Mason and Speedy (2002) conducted a study during Ironman New Zealand in 1997. This study was a first of its kind because it used the event as the laboratory. The task was to measure the energy balance during and Ironman Triathlon between men and women (Kimber et al, 2002). After an initial visit to a lab for vitals, the subjects, 8 females and 10 males, would participate in the 1997 Ironman New Zealand Race. Athletes need to monitor the type and quantity of food and fluid they consumed. Interviewers ran or cycled with the subject to get the information (Kimber et al, 2002).

The results of this study are very interesting. Men consumed more energy during the bike and the run than female athletes but the result was not statistically significant (Kimber et al, 2002). Energy consumption on the bike was responsible for 73% of total consumption (Kimber et al, 2002). Women took in more calories through food than liquid; women drank more than men; calories consumed during the cycle leg of the event had a positive relationship with finish time in women only (Kimber et al, 2002). This positive relationship of results and caloric intake on the bike was also found in a study by Downey and Hopkins (2001). The main difference between the two studies is the gender specificity of the Kimber study.

Downey and Hopkins did a random sample of 59 finishers of an Ironman distance event. They concluded: Finish time for 59 triathletes in an Ironman triathlon correlated highly with rates of carbohydrate and water intake (r = -0.65 and -0.51). Triathletes with below average intakes of carbohydrate and water can therefore expect to achieve worthwhile reductions in finish time of around 5% from moderate increases in intake (Downey & Hopkins, 2001).

Marc Evans, in his book Endurance Athletes Edge (1997), notes that carbohydrate replacement is crucial for competition, recovery and training. There is wide spread agreement that caloric intake during a race will help one get the best out of their training up to the event. Friel and Byrn, in their book Going Long (2003), also add that the timing of this intake is very important to performance as well.

The caloric intake, expenditure and balance listed from the Kimber study show an expenditure of 10,036 calories for men and 8570 for women, a mean intake of 3940 ± 868 for men and 3115 ± 914 for women and a negative balance of 5123 calories for women and 5973 calories for men (Kimber et al, 2002). The mean finishing time for the women was 12.6 hours and 12.0 hours for the men (Kimber et al, 2002). Evans concludes that one needs to ingest nearly 350 calories an hour to optimally fuel the event (Evans, 1997). This number seems to fall within the parameters for Kimber’s study. Ninety-three percent of the calories came from carbohydrates whether in liquid or solid form (Kimber et al, 2002). In Downey and Hopkins study, 94% of the calories were from carbohydrates (Downey & Hopkins, 2001).

These studies show the relationship between caloric intake and performance. They lay the foundation as to what an individual needs to do to perform at his best. The questions remains though; how do Joe and Jane triathlete think nutrition will help them and how will they go about maintaining their energy during and Ironman distance race? Since it is very difficult to take in nutrition during the first leg of the race, how will they incorporate the knowledge of these studies? What types of products will they use to ensure adequate energy intake? To get a better understanding of what age groupers do in a race, Michael Peters, a student at University of Phoenix, as a part of MAT561 devised as survey, Ironman Nutrition (2004) along the parameters of the class. The survey attempted to answer some of these questions.

Thirty one surveys were sent out by email to members of the Seattle Triathlon Club (SeaTri). Twenty studies were returned. The survey could only be completed by individuals who completed an ironman. There are a couple of interesting points. Of those who chose to partake in the survey, 70% had completed more than 2 ironman competitions (Peters, 2004). Forty-five percent have completed the Ironman triathlon in less then 12 hours, assuming no one has lied (Peters, 2004). Those who chose to complete the survey were experienced triathletes with above average finish times. The variance of this sample from the population of triathletes in SeaTri leads one to believe that those who chose to do this survey did so in an attempt to better their finish times. (Most subjects (98%) requested survey results.) All subjects in the study agreed with the statement: Ironman nutrition is just as important as training for the race. Ninety-two percent agreed that Ironman nutrition is highly personalized; what works for one athlete may not work for another (Peters, 2004). In an attempt to learn about how the athlete stores fuel for the first leg of the race, carbohydrate loading questions were asked among others. Here is where we see how individualized nutrition training can be (see following table).

Question	Always	Usually	Sometimes	Rarely	Never
I carbo-load the night before the race.	33%	17%	11%	22%	17%

I carbo-load during the week leading up to the race	39%	22%	17%	6%	17%

I eat a large breakfast the morning of the race	17%	17%	0%	33%	33%

I eat light or nothing at all the morning of the race	22%	11%	11%	0%	56%

I start my nutrition immediately on the bike regardless of how I feel	33%	17%	6%	17%	28%

I eat at regular intervals on the bike	78%	17%	6%	0%	0%

I start my drinking immediately on the bike regardless of how I feel	50%	22%	6%	0%	22%

I drink at regular intervals on the bike	78%	22%	0%	0%	0%

I bring my own nutrition regardless of what the race provides	72%	22%	0%	6%	0%

I train and race on the sponsored product regardless of what it is	11%	22%	17%	6%	44%

While there are some numerical discrepancies in how the subjects answered the listed questions, one gets a general idea that the time frame of nutrition leading up to the event until its completion is mixed across the board. It is obvious, however, that most of the athletes eat and drink at regular intervals and they supply most of their own nutrition.
The next question listed the general products which a triathlete consumed during the event. Ninety-four percent of the respondents drink water. Eighty-nine percent use energy gels. Eighty-three percent use electrolyte tablets or powder. Eighty-nine percent use an electrolyte replacement drink. Sixty-seven percent use a high calorie energy drink. Three of the twenty respondents used de-fizzled coke. One of the shortcomings of this part of the survey is that it did not specify any combinations. It is in this shortcoming the researcher failed to show any significant relationship to how individuals consume their calories. It is difficult to assume whether the subjects were responding to each question as a solitary entity or whether they were assuming the questions were meant in relation to the other products.

Finally, the survey asked to recall about how many calories each consumed during an Ironman triathlon. The range was from 1200 calories to 5500 calories. The mean caloric intake was 3447.5 calories. The mean finish time was 12.0 hours. This works out to be about 287.25 calories per hour. This study did not differentiate between male and female participants. This correlates with the two previous studies insomuch that the mean intake for the Kimber study was 3940± 868 calories (Kimber et al, 2002). However, ten of the twenty participants consumed insufficient calories. In terms of raw numbers, only half of the participants maintained adequate caloric intake in reference to the Kimber and Downey Studies. It is clear what is needed nutritionally for an athlete to successfully complete an Ironman triathlon. Several studies confirm the amount of carbohydrates and calories one relies on for fuel. Unfortunately, the researcher was not clear in a vital question to his hypothesis and therefore could not adequately demonstrate the individuality of ironman nutrition. His survey did however confirm the results of two other Ironman nutrition studies. While the study may be inconclusive, hopefully the survey helped those who participated in it by letting them reflect on their own practices in comparison to those of the studies mentioned.

References
Carlson, Tim (2002) Test Pilots of Triathlon Nutrition: The eternal search for bite stuff. Inside Triathlon 17(8).

Downey, B. and Hopkins, W. (2001) Nutrition Intake Predicts Performance in an Ironman Triathlon. Sportscience 5(1), Retrieved July 25, 2004 from www.sportsci.org/jour/0101/bmd.htm.

Evans, Marc (1997) Endurance Athletes Edge: Precision training and techniques for running. swimming, cycling and multisports. Champaign, IL: Human Kinetics.

Friel, Joe and Byrn, Gordon, (2003) Going Long: Training for Ironman Distance Triathlons. Boulder, CO: VeloPress.

Kimber, N., Mason, S., Ross, J., and Speedy, D. (2002) Energy Balance During an Ironman Triathlon in Male and Female Triathletes. International Journal of Sports Nutrition and Exercise Metabolism, 12, 47-62.

Peters, Michael (2004). [Individual responses to an Ironman nutrition survey]. Unpublished raw data.

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