Carbohydrate Loading For Ironman Triathlon – Infographic And Scientific Statement

NUTR12 Exercise & Sports Nutrition

Importance of Carbohydrate Loading in Ironman Triathlon

Carbohydrate Loading’ is a dietary strategy recommended for athletes, in the days leading into the start of an endurance event. The enhancement of present stores of glycogen in one’s muscles forms the crux of execution of carbohydrate loading (Bilku et al., 2014).

The following report is a scientific statement supporting the prepared info-graphic ‘Carbohydrate Loading for Ironman Triathlon’. The report outlines the primary purpose of carbohydrate loading, situations in sports where it has been shown to enhance performance as a pre-competition nutritional strategy, a list of nutritional and precautionary procedures. And lastly, the report highlights areas for future research.

Discussion

Carbohydrate loading is commonly utilized, for the enhancement of one’s energy sources, prior to the commencement of a sport or athletic activity requiring high intensity endurance exercise. This is performed through careful modifications of one’s diet, to increase the muscle glycogen reservoirs (Hackney, 2015).Importance of Carbohydrate Loading in Ironman Triathlon

Ironman Triathlon is characterized as a series of three types of races, which includes, firstly a swimming race of 2.4 miles, a bicycle riding event of 112 miles and lastly, a marathon running event of 26.22 miles (Kopetschny et al., 2018).

With respect to an Ironman Triathlon, athletes exhibit a wide range of metabolic changes, one of them being high rates of energy expenditure, as per their level of skill and competency. Hence, athletes new to the sport would require a low carbohydrate diet, in order to rely on fat oxidation for sustained energy supply. Experienced athletes exhibiting high rates of expenditure require high carbohydrate supplemented diet, along with careful reductions in exercise in order to mitigate the losses (Maunder, Kildingand & Plews, 2018). For the supply of energy, Adenosine Tri-phosphate or ATP is of utmost importance. The generation of Adenosine Tri-phosphate is conducted via the metabolism of carbohydrates (Hardy et al., 2015).

Despite the increased calorie content provided by fat, as compared to its carbohydrate counterpart, its metabolism by the human body generates energy in the form of ATP at rates which are not feasible for the athlete to exhibit endurance in high intensity sports. Carbohydrates hence, continue to remain faster sources of energy, and continuous engagement in strenuous, high intensity exercise stimulates the preservation of glycogen in the muscles of the human body (Vole, Noakes & Phinney, 2015).

During a situation of low glycogen stores, the metabolism to generate Adenosine Tri-phosphate is transmitted from carbohydrates to proteins, leading to gluconeogenic utilization of existing amino acids. Protein metabolism for energy generation, leads to a a negative nitrogen balance, causing muscle depletion. Hence, the implementation of carbohydrate loading diet in Ironman Triathlon, would be beneficial to metabolize carbohydrate as well fat, for a steady supply of energy (Arcega, Contreras & Orey, 2017).

Rationale

As opined by the Australian Institute of Sport, which is a part of the Australian Sports Commission, carbohydrate is often misinterpreted and misused (Trakman, 2016). Hence, the rationale behind studying carbohydrate loading is to impart awareness and education, regarding appropriate selection of food and exercise tapering (Wilson, 2015).

Rationale for Studying Carbohydrate Loading

Further in the study conducted by Kimber et al, (2002), it was found that the energy expenditure of male and female athletes engaged in ironman triathlon is far greater as compared to the intake of energy. According to the results, the energy expenditure in both males and females were found to be 10, 036 and 8570 calories respectively, while intake was calculated to be 3940 and 3115 calories respectively. Hence in accordance to the negative energy balance of -5973 calories in females and -5123 calories in males, the authors feel that the consumption of a high carbohydrate diet would be beneficial in reducing such nutritional and performance discrepancies in ironman triathlon athletes.

The athletes’ level of competency is positively associated with high rates of energy expenditure, as uncovered by the review performed by Maunder, Kildingand and Plews (2018). The authors also stated that ironman triathlon athletes exhibit a range of various metabolic changes, and hence modifying the carbohydrate and exercise routine as per their competence would be a beneficial method leading to improved performance. While a low carbohydrate diet associated with oxidization of fat would be beneficial for novice athletes, a tapered exercise plan, followed by external supplementation of carbohydrate would yield advantageous effects on professional ironman triathlon athletes.

Nutritional Recommendations

For the execution of carbohydrate loading, it is essential to perform the required amendments to one’s diet, through careful and calculated incorporation of carbohydrate-rich food sources, four to seven days preceding the high intensity or endurance event (Burke, van Loon & Hawley, 2016). As stated by the Australian Institute of Sport, an athlete weighing 70 kilograms and participating in an Ironman Triathlon, must consume a diet of 14-18 mega joules, consisting of 9 kilograms of carbohydrate per kilogram of body weight. This would amount to a total carbohydrate intake of 630 grams, a protein intake of 125 grams and fat intake of 60 grams per day (Mckay et al., 2018). The protein intake should include consumption of low fat or lean sources, such as vegetarian sources like beans and lentils, or lean meats like 60 grams of egg whites or 100 grams of fish per day, or even low fat milk proteins such as 1 cup of low fat yoghurt or soy milk, required for muscle repair. (Bean, 2017).

The athlete may then proceed to incorporation of carbohydrate rich food sources, preferably lighter and easily assimilated items such as 100-200 grams of fruits, 0.5-1 liter sweetened drinks, sweeteners like honey or jam and soluble fiber sources such as 60 grams of bagels and 60 grams of oats per day. The ingestion of high fiber carbohydrates is to be regulated, in order to prevent the possible occurrence of gastrointestinal discomfort. With progress of a carbohydrate loading diet, Ironman Triathlon athletes must considering increasing their water intake to an additional 1 to 2 liters, which will aid in beneficial weight and glycogen gain, since optimum glycogen storage and utilization requires additional water retention (Raman et al., 2014).

Carbohydrate Loading Diet Plan (As designed by the Author from FoodWorks)

Day	Meal	Food	Quantity
13-Nov-18	Breakfast	Oat bran	3 cups
Fruit salad,fresh,+apple+banana+berries	1 cup (diced)
Juice,100% juice,lemon,home squeezed	250 mL  (1 glass)
Snack	Muffin,apple,homemade	50g  (1, medium)
Honey	1 teaspoon
Gatorade 02 Perform Fierce Grape	500 mL (2 glasses)
Lunch	Sandwich,other,fresh	100g  (4 slices)
Bulla Fruit’n Yogurt Wildberry 97% Fat Free	250g  (1 cup)
Juice,100% juice,orange,home squeezed	375 mL  (1 large glass/1 can)
Snack	Smoothie,juice based,+berries	250 mL  (1 glass)
Muesli bar,other	50g  (1 bar)
Dinner	Pasta dish,homemade,in commercial sauce,cream based sauce,with chicken & vegetables	250g  (1 cup)
Bread rolls,with topping,spinach & fetta	100g  (2 rolls)
Juice,100% juice,fruit & vegetable blend,commercial,+apple+carrot+mango+orange+pineapple+passionfruit	250 mL  (1 glass)
Supper	Bagel,from white flour,toasted	75g  (1 large)
Fruit salad,fresh & dried fruit,homemade	2 cups (diced)

Nutritional Recommendations

Key Considerations

• For a successful carbohydrate loading diet, an athlete must engage in adequate rest, in order to prevent depletion of carbohydrate sources, before the commencement of the Ironman Triathlon event. Athletes must gradually engage in reduction of their exercise and training time, engaging in only 20 minutes of physical activity prior to two days before the event, followed by complete rest on the day before the same (Anderson et al., 2016).
• Often there is a discrepancy between the amount of carbohydrates required as compared to actual amount ingested by the athlete, due to lack of adequate knowledge and awareness regarding appropriate sources of carbohydrates. Hence, athletes must take active participation in formulating their diet plan, with the aid of a qualified sports nutritionist, in order to successfully achieve the beneficial impacts of the carbohydrate loading diet (Trakman et al., 2016).
• Consumption of foods high in insoluble fiber and bulky foods, may cause constipation, bloating and gastric discomfort. Hence, athletes must carefully select the foods to be consumed, and incorporate items which are quicker sources of carbohydrates, such as fruits, sweeteners, liquids and oats (Close et al., 2016).
• Weight gain is inevitable in the process of following a carbohydrate loading diet, which is indicative of the increased storage of glycogen in one’s muscles (Ørtenblad & Nielsen, 2015).
• It is common of some athletes to engage in excessive food consumption or faulty selection of foods, as an excuse to fulfill carbohydrate loading. Hence, athletes must be adequately informed regarding the salient features of the diet, and the possible negative consequences due to misconduct of the same (Wilson, 2015).
• It is imperative for Ironman Triathlon athletes to consume adequate electrolytes to prevent muscle spasms, with an intake of beverages containing 30-50 mmol of sodium per liter (Volek et al., 2015).

Literature Gaps and Future Research

As stated by the Nestle Nutrition Institute, there is a considerable lack of information about carbohydrate loading diet for female athletes. A majority of research has been performed utilizing male athletes (Close et al., 2016). Female athletes may require an increased consumption of carbohydrate rich foods as compared to males, due to decreased intake of energy (Devries, 2016). An additional concerning factor lacking research is the association between the female menstrual cycle and intake of carbohydrate loading diet.

Female athletes may exhibit decreased response to carbohydrate loading, in comparison to male athletes, during the occurrence of menstruation or follicular phase (Nindi et al., 2016). Despite limited evidence advocating the efficiency of carbohydrate loading during two weeks preceding the event of female menstruation, there is still requirement of conducting research, with respect to utilization of female athletes and sportspersons as subjects. (Heikura et al., 2017).

Conclusion

Hence, it can be concluded that, carbohydrate loading is an efficient way to enhance an athlete’s reservoirs of energy, with respect to performance during a high intensity and high endurance sports or activity such as Ironman Triathlon. However, the execution of such a diet would require careful selection and planning of foods and subsequent reduction in exercise, which athletes must adhere to, with respect to guidance from qualified professionals. Despite its proven efficiency, there is still a dearth of evidence regarding the effects of carbohydrate loading on female athletes, and hence, future research must be directed at achieving the same.

References

Amer, M. A., Smith, M. D., Herbison, G. P., Plank, L. D., & McCall, J. L. (2017). Network meta?analysis of the effect of preoperative carbohydrate loading on recovery after elective surgery. British Journal of Surgery, 104(3), 187-197.

Anderson, L., Orme, P., Di Michele, R., Close, G. L., Morgans, R., Drust, B., & Morton, J. P. (2016). Quantification of training load during one-, two-and three-game week schedules in professional soccer players from the English Premier League: implications for carbohydrate periodisation. Journal of sports sciences, 34(13), 1250-1259.

Arcega, R., Contreras, D., &Orey, J. (2017). Carbohydrate (CHO) loading does improve endurance performance.

Bean, A. (2017). The complete guide to sports nutrition. Bloomsbury Publishing.

Bilku, D. K., Dennison, A. R., Hall, T. C., Metcalfe, M. S., &Garcea, G. (2014). Role of preoperative carbohydrate loading: a systematic review. The Annals of The Royal College of Surgeons of England, 96(1), 15-22.

Burke, L. M., van Loon, L. J., & Hawley, J. A. (2016). Postexercise muscle glycogen resynthesis in humans. Journal of applied physiology, 122(5), 1055-1067.

Close, G. L., Hamilton, D. L., Philp, A., Burke, L. M., & Morton, J. P. (2016). New strategies in sport nutrition to increase exercise performance. Free Radical Biology and Medicine, 98, 144-158.

Devries, M. C. (2016). Sex?based differences in endurance exercise muscle metabolism: impact on exercise and nutritional strategies to optimize health and performance in women. Experimental physiology, 101(2), 243-249.

Hackney, A. C. (2015). Human Performance Enhancement in Sports and Exercise: Nutritional Factors-“Carbohydrate Loading”. RevistaUniversitaria de la EducaciónFísica y el Deporte, (2), 28-31.

Hardy, K., Brand-Miller, J., Brown, K. D., Thomas, M. G., & Copeland, L. (2015). The importance of dietary carbohydrate in human evolution. The Quarterly review of biology, 90(3), 251-268.

Heikura, I. A., Stellingwerff, T., Mero, A. A., Uusitalo, A. L. T., & Burke, L. M. (2017). A mismatch between athlete practice and current sports nutrition guidelines among elite female and male middle-and long-distance athletes. International journal of sport nutrition and exercise metabolism, 27(4), 351-360.

Kimber, N. E., Ross, J. J., Mason, S. L., & Speedy, D. B. (2002). Energy balance during an ironman triathlon in male and female triathletes. International journal of sport nutrition and exercise metabolism, 12(1), 47-62.

Kopetschny, H., Rowlands, D., Popovich, D., & Thomson, J. (2018). Long-Distance Triathletes’ Intentions to Manipulate Energy and Macronutrient Intake Over a Training Macrocycle. International journal of sport nutrition and exercise metabolism, 20(XX), 1-7.

Maunder, E., Kilding, A. E., & Plews, D. J. (2018). Substrate Metabolism During Ironman Triathlon: Different Horses on the Same Courses. Sports Medicine, 1-8.

McKay, A. K., Pyne, D. B., Peeling, P., Sharma, A. P., Ross, M. L., & Burke, L. M. (2018). The impact of chronic carbohydrate manipulation on mucosal immunity in elite endurance athletes. Journal of sports sciences, 1-7.

Nindl, B. C., Jones, B. H., Van Arsdale, S. J., Kelly, K., & Kraemer, W. J. (2016). Operational physical performance and fitness in military women: physiological, musculoskeletal injury, and optimized physical training considerations for successfully integrating women into combat-centric military occupations. Military medicine, 181(suppl_1), 50-62.

Ørtenblad, N., & Nielsen, J. (2015). Muscle glycogen and cell function–Location, location, location. Scandinavian journal of medicine & science in sports, 25, 34-40.

Raman, A., Macdermid, P. W., Mündel, T., Mann, M., &Stannard, S. R. (2014). The effects of carbohydrate loading 48 hours before a simulated squash match. International journal of sport nutrition and exercise metabolism, 24(2), 157-165.

Trakman, G., Forsyth, A., Devlin, B., &Belski, R. (2016). A systematic review of athletes’ and coaches’ nutrition knowledge and reflections on the quality of current nutrition knowledge measures. Nutrients, 8(9), 570.

Volek, J. S., Noakes, T., &Phinney, S. D. (2015). Rethinking fat as a fuel for endurance exercise. European journal of sport science, 15(1), 13-20.

Wilson, P. B. (2015). Misrepresentation of carbohydrate for exercise:‘It is time to bust the myth of physical inactivity and obesity: you cannot outrun a bad diet’. Br J Sports Med, bjsports-2015.

For infographic:

 Hackney, A. C. (2015). Human Performance Enhancement in Sports and Exercise: Nutritional Factors-“Carbohydrate Loading”. RevistaUniversitaria de la EducaciónFísica y el Deporte, (2), 28-31.

Kopetschny, H., Rowlands, D., Popovich, D., & Thomson, J. (2018). Long-Distance Triathletes’ Intentions to Manipulate Energy and Macronutrient Intake Over a Training Macrocycle. International journal of sport nutrition and exercise metabolism, 20(XX), 1-7.

McKay, A. K., Pyne, D. B., Peeling, P., Sharma, A. P., Ross, M. L., & Burke, L. M. (2018). The impact of chronic carbohydrate manipulation on mucosal immunity in elite endurance athletes. Journal of sports sciences, 1-7.

Raman, A., Macdermid, P. W., Mündel, T., Mann, M., &Stannard, S. R. (2014). The effects of carbohydrate loading 48 hours before a simulated squash match. International journal of sport nutrition and exercise metabolism, 24(2), 157-165.