Sports Nutrition: Macronutrients & Micronutrients
Sufficient intake of energy and nutrients necessary for the maintenance of life and protection of health and their proper use in the body means adequate and balanced nutrition. Whether an individual is an athlete or not, nutrition is important for the protection and development of health. Nutrition management in athletes is quite complex since it affects the athlete's body weight, body composition, exercise performance and recovery time. For this reason, it is essential to improve the performance of the athlete and the efficiency of the recovery period, and to ensure a net protein balance, in terms of planning energy and nutrients according to the exercise time. In this article, nutritional strategies for how and to what extent macro and micronutrients should be used in meals in athletes and their effects on performance are mentioned. There are two major classes of nutrients in food: macronutrients and micronutrients. Macro means big, and macronutrients take their name from the fact they make up the bulk of the nutrition in the food: carbohydrates, protein, and fat. These nutrients supply a human bosy with calories and serve as the building blocks for muscles and tissues. Vitamins and minerals, on the other hand, are micronutrients required by the body to carry out a range of normal functions. However, these micronutrients are not produced in our bodies and must be derived from the food consumed.
Various strategies have been developed for the sustainability of a healthy diet in athletes and individuals who do not do sports. These strategies are based on consuming the main food groups, except in special cases, such as nutrition in diseases and competition period nutrition. Except for those cases, the components that form the basis of the diet can be specified as follows: fruits, vegetables, lean animal or plant-based proteins, whole grains and low-fat dairy products. While consuming these main nutrients, it is expected that minimal or no packaged foods are consumed (Canada's food guide, 2021). In this way, athletes can easily meet the vitamins and nutrients it needs to be healthy and fit. At the same time, various diseases can be prevented due to the fact that processed foods tend to be higher in salt and sugar (Canada's food guide, 2021).
Figure 1: Healthy Eating Plate. Double Brain (n.d.).
The Healthy Eating Pyramid and the Healthy Eating Plate are other examples of strategies that suggest that certain amounts of each of the main nutrients should be consumed at meals. In addition, the Healthy Eating Pyramid includes aspects of a healthy lifestyle-exercise, weight control, vitamin D and multivitamin supplements, as well as moderation in alcohol for people who drink - so it is a useful tool for healthcare professionals and health educators. The Healthy Eating Pyramid can be thought of as a shopping list that should be added to the shopping cart every week. This list may consist of vegetables, fruit, whole grains, healthy fats and healthy proteins such as nuts, beans, fish and chicken, yogurt or other dairy products (Healthy Eating Plate, 2011).
Figure 2. Food pyramid chart. Alfaolga (n.d.).
Like the Canada food guides, The Eatwell Guide, and many other healthy eating strategies, the Harvard Healthy Eating Plate's main message is to focus on diet quality and consume a certain amount of essential food groups. The type of carbohydrate used in the diet is more important than the amount of carbohydrates in it. In addition, this strategy advises consumers to avoid sugary drinks, which often have little nutritional value, and to use healthy fats.
Figure 3: The Nutrition Source. Healthy Eating Plate (2011).
Most meals consist of vegetables and fruits (½ plate), whole grains (¼ plate) and protein (¼ plate (Healthy Eating Plate, 2011). There is no fixed nutrient intake for everyone, as daily nutritional needs will vary with age, physical activity levels, gender, body weight or various health conditions such as diabetes or hypercholesterolemia (McArdle, 2018). While the energy and nutrients required for nutrition may vary in different sports branches, there may be different energy and nutrient requirements among individuals who do the same sport (Altavilla et al., 2017).
If the importance of the basic food groups in the meals will be emphasized, carbohydrates, one of the main groups that should be consumed in meals, are the basic elements of sports nutrition for daily fuel requirement and recovery. Moreover, the need for carbohydrates can be diversified in line with different strategies according to the training types, the performance of the athlete, the type of sport, the competition period and the training period.
Figure 4. Harvest Display. Françoise Mouly (2019).
Pre-exercise meal planning, type of carbohydrate consumed, use of carbohydrate alone or with protein are the main points of pre-exercise nutrition (DeMarco et al., 1999; Kreider et al., 2007; Williams, 2007; Almada, 2019). Contribution to energy formation during exercise, improving performance, regenerating glycogen storage after exercise reveal its importance in sports nutrition (Phillips & Van Loon, 2011). During exercise, there are changes in the amount of many hormones with anabolic and catabolic effects, especially insulin and cortisol. The opposing effects of these hormones on each other trigger muscle breakdown and depleting of glycogen stores. When food is taken during exercise, insulin levels increase, while cortisol decreases (J. Ivy & Portman, 2004). Increased insulin secretion has a suppressive effect on cortisol, and muscle protein synthesis occurs by increasing the entry of carbohydrate into the cell (Benardot, 2012). Thus, liquid or solid foods, especially rich in carbohydrate content, taken during exercise have an increasing effect on exercise performance (Jeukendrup, 2004).
Pre-exercise meal planning, type of carbohydrate consumed, use of carbohydrate alone or with protein are the main points of pre-exercise nutrition (DeMarco et al., 1999; Kreider et al., 2007; Williams, 2007; Almada, 2019). Contribution to energy formation during exercise, improving performance, regenerating glycogen storage after exercise reveal its importance in sports nutrition (Phillips & Van Loon, 2011). During exercise, there are changes in the amount of some hormones with anabolic and catabolic effects, especially insulin and cortisol. The opposing effects of these hormones on each other trigger muscle breakdown and depleting of glycogen stores. When food is cosumed during exercise, insulin levels increase, while cortisol decreases (J. Ivy & Portman, 2004). Increased insulin secretion has a suppressive effect on cortisol, and muscle protein synthesis occurs by increasing the entry of carbohydrate into the cell (Benardot, 2012). Thus, liquid or solid foods, especially rich in carbohydrate content, consumed during exercise have an increasing effect on exercise performance (Jeukendrup, 2004).
Figure 5: New ways to make food are coming. (Pascual, 2021).
Taking protein along with carbohydrates in the main meal or snack increases effectiveness by improving glycogen stores (Burke et al., 2011; Kreider et al., 2007). Carbohydrate intake can be timed to fuel uptake during training sessions during the day. Additionally, protein and nutrient-rich carbohydrate foods or meal combinations can help the athlete achieve other acute or chronic sports nutrition goals.
Table 1. Summary of guidelines for carbohydrate intake by athletes (Burke et al., 2011).
Exercise Intensity | Situation | Carbohydrate Targets |
Light | Low intensity or skill-based activities | 3–5 g/kg of athlete’s body mass (BM)/ day |
Moderate | Moderate exercise program (i.e., ~1 h/day) | 5–7 g/kg/day |
High | Endurance program (e.g., 1–3 h/day moderate high intensity exercise) | 6–10 g/kg/day |
Very high | Extreme commitment (i.e., >4–5 h/day moderate high intensity exercise | 8–12 g/kg/day |
Consuming carbohydrates during core training sessions to include pre-workout intake and refueling during and after the session can improve performance and recovery. Also, focusing on eating during training sessions helps the athlete automatically meet their energy and carbohydrate intake with changing needs.
Table 2. Special Timing of Intake to Support Key Training Session(Burke et al., 2011).
|
|
|
|---|---|---|
|
|
|
|
|
|
|
|
|
|
|
|
Proteins are another main food group that is very important for athletes, as carbohydrates. Proper planning of protein intake provides the athlete with advantages in terms of accelerating muscle synthesis and repair, improving muscle glycogen stores, improving sleep quality, keeping blood glucose levels constant and creating a better glycemic response (Austin, 2011; Ormsbee et al., 2014). Moreover, the muscle breakdown that occurs in the muscles after exercise should be tried to be corrected. Muscle repair is aimed by increasing insulin levels with the use of amino acids (Aragon & Schoenfeld, 2013). In addition, according to studies examining the recommended consumption amounts of proteins, daily protein requirement has been reported as 0.8-1.0 g/kg/day in sedentary individuals, 1.2-1.4 g/kg/day in endurance athletes, and 1.2-1.7 g/kg/day in resistance athletes (Rodriguez et al., 2009).
Furthermore, it can be consumed as a pre-exercise meal 3-4 hours before exercise, together with 0.15-0.25 g/kg body weight/day protein, 1-2 g/kg body weight/day carbohydrate (Tarnopolsky et al., 2005; Kerksick et al., 2008). This amount may vary depending on the duration of the exercise performed by the athlete and the form of the individual (Dawson, 2002; Kerksick et al., 2008). It can be used during exercise due to the contribution of proteins to energy generation, regulating muscle breakdown and improving performance (Phillips & Van Loon, 2011). It is estimated that consumption of carbohydrates (0.15 g/kg/h) and protein hydrolyzate (0.15 g/kg/h) during exercise and during the early recovery period stimulates muscle protein synthesis and increases whole body protein synthesis (M. Beelen et al., 2008). In addition, it is recommended that the carbohydrate protein ratio be 3-4:1(Kerksick et al., 2008; Potgieter, 2013).
Figure 6. Omega fat concept. Unknown (n.d.).
Regarding the use of fats, athletes need to consume about 30% of their daily energy needs, as sedentary individuals diet. For athletes aiming for fat loss, 0.5-1g/kg/day fat consumption is recommended (Kreider et al., 2010). It is known that those who consume less than 40 g of fat per day are more successful in losing and maintaining body weight(Miller, 2001). Considering essential fatty acid intakes, omega 3 fatty acid needs should meet 0.6-1.2% of daily energy needs, and omega 6 should meet 5-10%. Thus, the required 3-5:1 omega 6:omega 3 ratio is provided, while this ratio increases up to 10:1, 20:1 with western-style nutrition. The total omega 3 requirement can be calculated as 1-2 g per day and the EPA:DHA ratio is expected to be 2:1(Simopoulos, 2007).
Athletes who consume a limited energy and low-fat diet and limit their vegetable and fruit consumption may need additional supplementation to meet their adequate vitamin and mineral needs(Thomas et al., 2016).
Table 3. Antioxidant vitamins and their potential effects on athletic performance(Potteiger, 2011).
Vitamin | Role in Athletic Performance |
E | Acts as an antioxidant to prevent cell damage |
B1 | Takes part in carbohydrate metabolism |
B2 | Takes part in carbohydrate metabolism |
B3 | Takes part in energy metabolism |
B6 | Takes part in amino acid and glycogen metabolism |
Pantothenic Acid | Takes part in energy metabolism |
Folate | Important for amino acid metabolism |
B12 | Important for amino acid metabolism |
Biotin | Takes part in amino acid and glycogen metabolism |
C | Acts as an antioxidant to prevent cell damage |
It is speculated that thiamine (B1) deficiency may result in decreased availability of succinate, a component of heme, and lead to insufficient hemoglobin formation, another factor that may affect aerobic exercise capacity. A good linear relationship was noted between thiamine intake and energy intake(Van der Beek, 1994). It is very important to provide adequate amounts of vitamin B2 for athletes to protect their cells' energy metabolism, hormonal balance, endurance, immunity and cardiovascular health(Gromova, et al., 2019). It is known that vitamin B2 supplementation has positive effects on aerobic capacity in athletes and that it also accelerates recovery in strength athletes(Gromova et al., 2019). Niacin (B3) requirement is also generally related to energy intake, and it can be said that athletes with a large energy intake need a proportionally higher intake of niacin. High doses of niacin supplementation can suppress free fatty acid release through reduced lipolysis, resulting in reduced availability of the main fuel source. It forces muscles to rely more on glycogen stores, which is thought to negatively affect long-term exercise performance(Williams 1985; Clarkson 1991). The exercise process stresses the metabolic pathways that use vitamin B6, and the need for this vitamin increases in athletes and active individuals (Manore 1994).
Folic acid and vitamin B12 are important for protein synthesis, tissue building and repair. Folic Acid (B9) deficiency can cause anemia, and a deficiency can affect aerobic endurance performance, at least in theory(Maughan, 2013). By increasing the availability of micronutrients, it is possible to increase maximum aerobic power, achieve better performance results, and provide adequate recovery after competition or intense training(Gromova et al., 2019). Due to its role in energy metabolism, B12 is used to increase energy, improve athletic performance and endurance. There is also the view that B12 supplementation does not have a beneficial effect on performance(Lukaski, 2004). It is also an essential component in the formation and function of red blood cells. Because of this role, it is sometimes thought by athletes and their trainers that vitamin B12 supplementation should increase the oxygen-carrying capacity of the blood and improve performance in events where oxidative metabolism is important (Maughan, 2013).
According to studies, vitamin C supplementation applied to sedentary individuals increases muscle thrust (Evans et al., 2017). The most significant effect of vitamin C supplementation on sports performance is in athletes with low vitamin C levels(Paschalis et al., 2016).
Figure 7: Products rich of vitamins, minerals for health cartoon vector illustrations set. (Nesterenko, n.d.)
It has been suggested that extra vitamin A is needed in athletes who require good visual acuity and alertness and during periods of stress(Williams, 1985). Vitamin D supplementation has been shown in many studies to affect muscle performance, kinetics, and efficiency (Sikora-Klak et al., 2018). Vitamin D deficiency can negatively affect athletic performance by affecting training quality, injury frequency and duration of the athlete (Halliday et al., 2011). A vitamin D level below 32 ng/ml may negatively affect performance (Cannel et al., 2009). It is suggested that vitamin D levels above 40 ng/ml prevent bone fractures. For optimal musculoskeletal protection; vitamin D level should be above 30 ng/ml (Glowacki, 2007). In general, it is advised that vitamin D concentration be above 32 ng/ml or even over 40 ng/ml in athletes(Larson-Meyer and Willis, 2010). If vitamin D deficiency (<30ng/mL) is present in the athlete, it has been stated that it is necessary to load 50,000 IU of vitamin D per week for 8 weeks with supplementation protocols(Holick, 2017). After about 90 days, the steady state of vitamin D is reached (Heaney, 2003). It is recommended that vitamin D level be retested at 3 months after supplementation is complete. If vitamin D level remains below 30 ng/mL, supplementation protocol should be repeated for another 8 weeks and then retested. (Holick, 2017). It is stated that vitamin E may play a role in reducing muscle damage and oxidative stress, as demonstrated by a reduction in muscle-specific enzyme levels in serum after strenuous exercise (Rokitzki, et al., 1994). Vitamin deficiencies can result in decreased exercise performance, and vitamin supplements have been shown to improve performance in people with pre-existing vitamin deficiency. Athletes participating in strenuous training may need monitoring of their vitamin status, even if they consume the recommended daily intake of the vitamin. Vitamin supplements may be recommended for athletes in special conditions, including those on a weight loss diet, those with eating disorders, or those with low energy intake. Excessive intake of fat-soluble vitamins can accumulate to levels that can be toxic. Prolonged excessive intake of water-soluble vitamins can also be harmful and cause nutritional imbalances. Paying attention to food choices rather than a specific supplement can be an important strategy.
It is very important for athletes to get enough calcium. They can reduce the risk of stress fractures by helping to keep their bones healthy and strong, which allows them to maintain their performance(Nguyen, 2011). Depletion of body iron stores is common, especially in female athletes. Iron deficiency may or may not be anemia, and it is characterized by impaired muscle function and decreased athletic capacity(Lukaski, 2004; Brownlie, 2004; Wolinsky, 2005; Whiting, 2006; Rodriguez et al., 2009). Sodium is a very important electrolyte for athletes with high sweat loss(Bergeron, 2003; Kenny, 2004; Palmer and Spriet 2008; Sawka et al., 2007). In addition to carbohydrates, sports drinks containing sodium (0.5-0.7 g.L-1) and potassium (0.8 2.0 g.L-1) can be used, especially in endurance competitions (>2 hours)(Volpe ,2006; Kenney, 2004; Palmer & Spriet, 2008; Sawka et al., 2007)
It is known that diet affects exercise response and performance. The body's adaptation to exercise is the result of changes in the expression of genes mediated not only by exercise but by many factors, including the interaction between exercise, nutrients, and genetic diversity. Macronutrient intake varies according to the energy needs of the athlete. Genetic variations or polymorphisms in genes encoding proteins have been shown to affect individual nutrient requirements and catalytic activity in metabolism. Although studies examining dietary factors and genetics reveal that dietary fat and protein intakes may have more modifying effects on body composition than carbohydrates, all macronutrients are critical to athlete performance. Studies on athletes show that athletes who are involved in endurance and power sports have different genetic characteristics. It is extremely important that genetic information can give an idea about which type of sport a person can be more successful in.
In summary, the effects that can be created as a result of the use of foods from meals to what extent and in what way are mentioned. In this context, it is important to pay attention to the intake of macro and micro elements before, during and after exercise, being carbohydrats the most emphasized nutrient. Carbohydrates are essential for replenishing and increasing muscle glycogen stores, which is one of the main purposes of exercise. In addition, the prevention of protein breakdown and muscle loss is one of the other very important goals, and although the most important nutrient is proteins, protein loss is also prevented by improving muscle glycogen stores. Consuming carbohydrates together with proteins provides the best benefit from exercise. It is very important to consume an adequate and balanced diet, plan the mealtime and get enough energy and nutrients before the competition and exercises. While muscle tissue should provide a strong output during exercise, it can be destroyed due to insufficient intake of energy and nutrients. In order to support the performance of the athlete seven days before competitions, the athlete should rest and excessive exercise should be avoided. The athlete's muscle and liver glycogen stores should be filled and the athlete should be provided with adequate fluid intake. A good level of hydration also provides benefits in the development of glycogen stores.
Bibliographical References
Aragon, A. A., & Schoenfeld, B. J. (2013). Nutrient timing revisited: is there a post-exercise anabolic window? Journal of the International Society of Sports Nutrition, 10 (1), 5.
Almada, A. L. (2019). Carbohydrate and muscle glycogen metabolism: exercise demands and nutritional influences. Nutrition and Enhanced Sports Performance (pp. 395-406). Academic Press.
Altavilla, G., Riela, L., Di Tore, A. P., & Raiola, G. (2017). The physical effort required from professional football players in different playing positions. Journal of Physical Education and Sport, 17(3), 2007-2012.
Austin, K. G., & Seebohar, B. (2011). Performance nutrition: Applying the Science of Nutrient Timing. Human Kinetics.
Beelen, M., Koopman, R., Gijsen, A. P., Vandereyt, H., Kies, A. K., Kuipers, H., & van Loon, L. J. (2008). Protein coingestion stimulates muscle protein synthesis during resistance-type exercise. American Journal of Physiology-Endocrinology and Metabolism, 295(1), E70-E77.
Bergeron, M. F. (2003). Heat cramps: fluid and electrolyte challenges during tennis in the heat. Journal of Science and Medicine in Sport, 6(1), 19-27.
Brownlie IV, T., Utermohlen, V., Hinton, P. S., & Haas, J. D. (2004). Tissue iron deficiency without anemia impairs adaptation in endurance capacity after aerobic training in previously untrained women. The American Journal of Clinical Nutrition, 79(3), 437-443.
Burke, L. M., Hawley, J. A., Wong, S. H., & Jeukendrup, A. E. (2011). Carbohydrates for training and competition. Journal of Sports Sciences, 29(sup1), S17-S27.
Canada's food guide, (2021). Make healthy meals with Canada’s food guide plate. Goverment of Canada.
https://food-guide.canada.ca/en/tips-for-healthy-eating/make-healthy-meals-with-the-eat-well-plate/ Accessed 4 September 2022.
Cannell, J. J., Hollis, B. W., Sorenson, M. B., Taft, T. N., & Anderson, J. J. (2009). Athletic performance and vitamin D. Medicine & Science in Sports & Exercise, 41(5), 1102-1110. Dawson, W. J. (2002). American College of Sports Medicine, American dietetic association, and dietitians of Canada: nutrition and athletic performance (joint position statement). Medical Problems of Performing Artists, 17(1), 51-53.
DeMARCO, H. M., Sucher, K. P., Cisar, C. J., & Butterfield, G. E. (1999). Pre-exercise carbohydrate meals: application of glycemic index. Medicine and Science in Sports and Exercise, 31(1), 164-170.
Evans, L. W., Zhang, F., & Omaye, S. T. (2017). Vitamin C supplementation reduces exercise-induced oxidative stress and increases peak muscular force. Food and Nutrition Sciences, 8(08), 812.
Glowacki, J. (2007). Vitamin D inadequacy in 2007: what it is and how to manage it. Current Opinion in Orthopaedics, 18(5), 480-485.
Gromova, O., Torshin, I. Y., Sorokina, M., & Gromov, A. (2019). Magnesium and vitamin B2 supplementation is an important nutritional resource of sports medicine. Journal: Medical Council (21), 216, 230. Halliday, T. M., Peterson, N. J., Thomas, J. J., Kleppinger, K., Hollis, B. W., & Larson-Meyer, D. E. (2011). Vitamin D status relative to diet, lifestyle, injury, and illness in college athletes. Medicine and Science in Sports and Exercise, 43(2), 335-343.
Healthy Eating Plate (2011). The Nutrition Source. Harvard T. H. Chan School of Public Health. https://www.hsph.harvard.edu/nutritionsource/healthy-eating-plate/ Accessed 4 September 2022.
Heaney, R. P., Davies, K. M., Chen, T. C., Holick, M. F., & Barger-Lux, M. J. (2003). Human serum 25-hydroxycholecalciferol response to extended oral dosing with cholecalciferol. The American Journal of Clinical Nutrition, 77(1), 204-210. Holick, M. F. (2017). The vitamin D deficiency pandemic: Approaches for diagnosis, treatment and prevention. Reviews in Endocrine and Metabolic Disorders, 18(2), 153-165.
Ivy, J., & Portman, R. (2004). Nutrient Timing: The Future of Sports Nutrition. Basic Health Publications, Inc.
Jeukendrup, A. E. (2004). Carbohydrate intake during exercise and performance. Nutrition, 20(7-8), 669-677.
Jeukendrup, A., & Baker, L. (2016). Carbohydrate, sports drinks and performance: Strategies for Olympic sports Nutrition: from the training to the competition. Nutrition and Performance in Sport, Vol. Part 1, pp. 30-36.
Kenney, W. L. (2004). SSE# 92: Dietary Water and Sodium Requirements For Active Adults. Sports Science, 17(1), 92. Kerksick, C., Harvey, T., Stout, J. et al. (2008). International Society of Sports Nutrition position stand: Nutrient timing. Journal of the International Society of Sports Nutrition. 5, 17.
Kreider, R. B., Earnest, C. P., Lundberg, J., Rasmussen, C., Greenwood, M., Cowan, P., & Almada, A. L. (2007). Effects of ingesting protein with various forms of carbohydrate following resistance-exercise on substrate availability and markers of anabolism, catabolism, and immunity. Journal of the International Society of Sports Nutrition, 4(1), 18. Kreider, R. B., Wilborn, C. D., Taylor, L., Campbell, B., Almada, A. L., Collins, R., & Antonio, J. (2010). ISSN exercise & sport nutrition review: research & recommendations. Journal of the International Society of Sports Nutrition, 7(1), 7. Larson-Meyer, D. E., & Willis, K. S. (2010). Vitamin D and athletes. Current Sports Medicine Reports, 9(4), 220-226. Lukaski, H. C. (2004). Vitamin and mineral status: effects on physical performance. Nutrition, 20(7-8), 632-644.
Maughan RJ. (Ed.), (2013). Sports Nutrition, Volume XIX The Encyclopaedia of Sports Medicine, an IOC Publication. John Wiley & Sons. McArdle, W. D. (2018). Sports and Exercise Nutrition. Lippincott Williams & Wilkins. Miller, W. C. (2001). Effective diet and exercise treatments for overweight and recommendations for intervention. Sports Medicine, 31(10), 717-724. Nguyen, V. H. (2011). Calcium For Athletes to Improve Bone Strength and Health. NSCA’S Performance Training Journal, 9, 9-11. Ormsbee, M. J., Bach, C. W., & Baur, D. A. (2014). Pre-exercise nutrition: the role of macronutrients, modified starches and supplements on metabolism and endurance performance. Nutrients, 6(5), 1782-1808. Palmer, M. S., & Spriet, L. L. (2008). Sweat rate, salt loss, and fluid intake during an intense on-ice practice in elite Canadian male junior hockey players. Applied Physiology, Nutrition, and Metabolism, 33(2), 263-271. Paschalis, V., Theodorou, A. A., Kyparos, A., Dipla, K., Zafeiridis, A., Panayiotou, G., & Nikolaidis, M. G. (2016). Low vitamin C values are linked with decreased physical performance and increased oxidative stress: reversal by vitamin C supplementation. European Journal of Nutrition, 55(1), 45-53.
Phillips, S. M., & Van Loon, L. J. (2011). Dietary protein for athletes: from requirements to optimum adaptation. Journal of Sports Sciences, 29(sup1), S29-S38.
Potgieter, S. (2013). Sport nutrition: A review of the latest guidelines for exercise and sport nutrition from the American College of Sport Nutrition, the International Olympic Committee and the International Society for Sports Nutrition. South African Journal of Clinical Nutrition, 26(1), 6-16.
Potteiger, J. A. (2011). ACSM's Introduction to exercise science: Wollters Kluwer.
Rodriguez, N. R., Di Marco, N. M., & Langley, S. (2009). American College of Sports Medicine position stand. Nutrition and Athletic Performance. Medicine and Science in Sports and Exercise, 41(3), 709-731. Rodriguez, N. R., DiMarco, N. M., & Langley, S. (2009). Position of the American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and athletic performance. Journal of the American Dietetic Association, 109(3), 509-527. Rokitzki, L., Logemann, E., Huber, G., Keck, E., & Keul, J. (1994). α-Tocopherol supplementation in racing cyclists during extreme endurance training. International Journal of Sport Nutrition and Exercise Metabolism, 4(3), 253-264. Sawka, M. N., Burke, L. M., Eichner, E. R., Maughan, R. J., Montain, S. J., & Stachenfeld, N. S. (2007). American College of Sports Medicine position stand. Exercise and fluid replacement. Medicine and Science in Sports and Exercise, 39(2), 377-390.
Sikora-Klak, J., Narvy, S. J., Yang, J., Makhni, E., Kharrazi, F. D., & Mehran, N. (2018). The effect of abnormal vitamin D levels in athletes. The Permanente Journal, 22. Simopoulos, A. P. (2007). Omega-3 fatty acids and athletics. Current Sports Medicine Reports, 6(4), 230-236. Tarnopolsky, M. A., Gibala, M., Jeukendrup, A. E., & Phillips, S. M. (2005). Nutritional needs of elite endurance athletes. Part I: Carbohydrate and fluid requirements. European Journal of Sport Science, 5(1), 3-14.
Thomas, D. T., Erdman, K. A., & Burke, L. M. (2016). Nutrition and thletic performance. Medicine and Science in Sports and Exercise, 48, 543-568. Whiting, S. J., & Barabash, W. A. (2006). Dietary reference intakes for the micronutrients: considerations for physical activity. Applied Physiology, Nutrition, and Metabolism, 31(1), 80-85. Williams, M.H. (1985) The role of vitamins in physical activity. In Nutrition Aspects of Human Physical and Athletic Performance, Nutirition in Exercise and Sports Series, Charles C. Thomas, Springfield, IL. 2nd edn (ed. M.H. Williams), pp. 147–185.
Williams, C. (2007). Carbohydrate as an energy source for sport and exercise. Nutrition and Sport, 41, 71. Wolinsky, I., & Driskell, J. A. (Eds.). (2005). Sports Nutrition: Vitamins and Trace Elements. CRC Press.
Van der Beek, 1994). Thiamin, riboflavin and vitamin B6: impact of restricted intake on physical performance in man. Journal of the American College of Nutrition, 13(6), 629-640. Volpe, S., & Bland, E. (2006). Vitamins, minerals and exercise. Sports Nutrition: A Practice Manual for Professionals. Chicago (IL): American Dietetic Association, 61-3.
Visual Sources
Figure 1 : Double Brain (n.d.). Healthy Eating Plate. [Photograph]. Retrieved from
Figure 2. Alfaolga. (n.d.). Food pyramid. [Photograph]. Adobe Stock. Retrieved from
Figure 3: Healthy Eating Plate (2011). The Nutrition Source. Harvard T. H. Chan School of Public Health. https://www.hsph.harvard.edu/nutritionsource/healthy-eating-plate/ Accessed 4 September 2022.
Figure 4: Mouly, F., (2019). Harvest Display. [Photograph]. The New Yorker. Retrieved from
https://www.newyorker.com/culture/cover-story/cover-story-2019-11-25
Figure 5: . (Pascual, 2021). New ways to make food are coming - but will consumers bite? [Photograph]. The Economist. Retrieved from https://www.economist.com/leaders/2021/10/02/new-ways-to-make-food-are-coming-but-will-consumers-bite
Figure 6. Unknown (n.d.). Omega fat concept. [Photograph]. Retrieved from https://www.freepik.com/premium-vector/omega-fat-concept-people-take-products-vitamins-with-polyunsaturated-fatty-acids-natural-organic-food-with-high-omega-cartoon-flat-illustration_13292333.htm
Figure 7: Nesterenko, (n.d.). Products rich of vitamins, minerals for health cartoon vector illustrations set. Retrieved from https://www.alamy.com/products-rich-of-vitamins-minerals-for-health-cartoon-vector-illustrations-set-image384564845.html
Comments