Introduction
Many athletes are intrigued about the topic of nutrition for many reasons, but one of the main goals of all athletes is to improve performance, and adequate nutrition practices play a role not only in performance, but also in recovery. Both the type of food consumed and the timing of consumption are factors in both performance and recovery. Therefore, it is very important to understand what the different macro and micronutrients are and the individual roles they all play in the body. Different athletes will require different nutritional demands, as each individual athlete is different. While there are many different ideologies on nutritional diets, based on factors such as goals, beliefs, religion, and food intolerances, one ideology remains the same: adequate nutrition is required for athletes to maintain in good health standing. The ultimate goal of this guide is to provide basic information on what the macro and micronutrients are, the role they play in the body for athletes, dosing and timing, supplement usage, and mindfulness of dietary practices.
Macronutrients and Micronutrients in the Body
A primary concern for all athletes should be to consider whether or not their total caloric intake is supportive of their goals and expenditure during rigorous training and practices. The macronutrients consist of protein, carbohydrates and fats/lipids, and are the larger nutrients required by our bodies in greater quantities (Whitney & Rolfes, 2005). These nutrients are organic and essential, being required by the body and provide the body with energy (Whitney & Rolfes, 2005). The micronutrients consist of both vitamins and minerals which are required in smaller doses and do not yield energy within the body (Whitney & Rolfes, 2005).
Carbohydrates in our diets function to provide our cells and central nervous system with energy in the form of glucose by providing 4 kcals per gram of carbohydrate consumed. The glucose provided from the diet can then be stored both within the liver and the muscles as glycogen. Adequate carbohydrate intake will also provide the body with a protein sparring effect by reducing or preventing proteins use for cellular energy (Whitney & Rolfes, 2005). Carbohydrates in our diet also provide us with starches and fibers which play integral roles in weight management, the lowering of blood cholesterol levels and normal bowel motility (Whitney & Rolfes, 2005).
Fats function as a high energy source providing 9kcals per gram consumed and provide energy reserves when stored in body fat tissue, which also protects our bodies against shock and extreme temperatures (Whitney & Rolfes, 2005). Adequate consumption of fat is necessary for proper carbohydrate and protein use in the body, but in the absence of sufficient glucose, fats can be utilized as an alternate energy source (Whitney & Rolfes, 2005). In addition to these functions, the fat soluble vitamins A, D, E and K all require fats for storage and absorption.
Proteins actually contain a large number of physiological functions outside of growth and maintenance of various body structures such as the bones, muscles, organs, tendons, membranes and skin (Whitney & Rolfes, 2005). Proteins also function as enzymes to facilitate chemical reactions, as hormones, and as regulators of fluid and acid-base balances (Whitney & Rolfes, 2005). Proteins can also function as transporters in the body, such as the case of hemoglobin delivering oxygen to tissues around the body, function as antibodies and finally also as a source of energy providing 4 kcals per gram of protein consumed yielding the same amount of energy as a carbohydrate per gram (Whitney & Rolfes, 2005).
The micronutrients which consist of vitamins and minerals also provide their own unique set of functions within the body. Vitamins regulate a number of neurological and metabolic functions within the body and play vital roles in energy synthesis and metabolism and the prevention of cell destruction (Kerksick, Wilborn, Roberts, Smith-Ryan, Kleiner, Jager, Collins, Cooke, Davis, Galvan, Greenwood, Lowery, Wildman, Antonio, & Kreider, 2018). Vitamins can be classified as being water soluble, which include vitamin C and all of the B vitamins, or fat soluble, which include vitamins A, D, E and K (Kerksick et al., 2018). Minerals also can be categorized into two groupings consisting of first the major minerals, sodium, chloride, potassium, calcium phosphorous, magnesium and sulfur. The major minerals influence fluid balance within the body, direct nerve impulse transmissions and muscle contractions and are involved in regulating blood pressure (Kerksick et al., 2018). They also participate in reactions involving glucose, amino acids, fatty acids and vitamins (Whitney & Rolfes, 2005). The second category of minerals is the trace minerals, which consists of iron, zinc, iodine, selenium, copper, manganese, fluoride, chromium and molybdenum (Whitney & Rolfes, 2005). These also functions as key contributors to tissue structures, as hormone and enzyme components and also as regulators of neurological and metabolic functions (Kerksick et al., 2018).
Macro and Micronutrient Guidelines: Sources, Roles, Dosing, and Timing
According to the literature, athletes should be aiming for a total of 40-70kcals per kg per day, due to the typical high energy demands (Kerksick et al., 2018). This is typically defined as participating in moderate intensity training protocols which consist of 2-3hr per day for 5-6 times per week or high volume workloads consisting of 3-6hrs in 5-6days per week in 1-2 workouts (Kerksick et al., 2018). Athletes weighing in the 50-150kg weight range should be involved in the aforementioned intensities and volume of training should be aiming to consume 5-8g of carbohydrate per kilogram of bodyweight (Kerksick et al., 2018). This intake should properly ensure adequate maintenance of muscle glycogen stores (Kerksick et al., 2018). It is highly recommended for athletes to consume the majority of their carbohydrates from complex carbohydrates, whole grains, fruits and vegetables. Athletes participating in multiple training or practice sessions throughout the day should be concerned with glycogen resynthesis, and should be aiming to consume 1.2g of high glycemic carbohydrates per kg per hour for the initial four hours following the completion of training (Kerksick et al., 2018). The addition of small doses of caffeine with protein and carbohydrates post-workout has also been shown to promote an accelerated rate of glycogen restoration (Kerksick et al., 2018). Consumption of 0.7g of carbohydrate per kg per hour during exercise in a 6-8% fluid solution is also recommended for those athletes participating in extended bouts of training, every 10-15mins throughout the session (Kerksick et al., 2018).
Protein intake is also critical for athletes and should be approximately 1.2-2g per kg per day to properly maintain protein balance (Kerksick et al., 2018). Inability to consume this amount can negatively impact recovery and promote a negative nitrogen balance ion the body, indicative or the athlete reaming within a catabolic state (Kerksick et al., 2018). Athletes who are involved in intensity activity should actually be aiming to consume 1.7-2.2g per kg per day and even higher intakes of 2.3-3.1g per kg of fat free mass may be required for athletes during hypo caloric periods (Kerksick et al., 2018). In addition to the total daily intake, athletes need to be concerned with the quality of their protein as the differences in amino acids and peptides from varying protein sources and digestion rates from the source will impact biological activity (Kerksick et al., 2018). High quality protein sources are recommended to come from skinless chicken, lean cuts of red meats, fish, eggs and even protein supplements (Kerksick et al., 2018). With regards to timing of this macro nutrient, it should be ideally spaced throughout the course of the day with protein feedings consumed every 3-4hrs, with high quality protein being consumed either before a workout or immediately afterwards to promote a strong increase in muscle protein synthesis (Kerksick et al., 2018).
Fat consumption recommendations are highly dependent upon the athlete’s goals and training status (Kerksick et al., 2018). Most athletes should be aiming to maintain a total of 30% of their daily total caloric intake from fat (Kerksick et al., 2018). In instances in which athletes participate in high volume training can consume percentages as high as 50% of daily total caloric intakes from fat (Kerksick et al., 2018). Intakes as low as 20% of daily total caloric intake or 0.5-1g per kg per day of bodyweight is also an acceptable intake for athletes focused on reducing excess body fat (Kerksick et al., 2018).
Dosing and timing of micronutrients such as vitamins and minerals is also essential and of concern to athletes. According to the literature, vitamins have not been reported to provide any sort of ergogenic affects to athletes outside of health benefits from certain vitamins (Kerksick et al., 2018). Only in the presence of a vitamin deficiency, have supplementation and dietary modifications to correct nutritional status, yielded increases in both an athlete’s health status and performance (Kerksick et al., 2018). Supplementation of a multivitamin and mineral supplement may be more so warranted for those athletes who are nutritionally deficient or with goals of cutting excess body fat and are therefore nutritional in an energy deficit (Kerksick et al., 2018). Minerals, like vitamins, can become deficient among athletes secondary to training endeavors. These reductions and deficiencies can yield decreased exercise capacity, most notably when sodium, potassium and magnesium (Kerksick et al., 2018). Supplementation is key for deficiency, however, no ergogenic effects have been noted from supplementation in populations receiving adequate nutrition (Kerksick et al., 2018). There exist a few exceptions, where mineral supplementation may offset negative effects of training, dieting or excessive training. For example: calcium supplementation may support bone mass density in female athletes suffering from the female athlete triad and susceptible to premature osteoporosis and iron supplementation can also help offset anemia and zinc supplementation can offset immune system changes (Kerksick et al., 2018). Finally, sodium levels, such as sodium phosphate can improve anaerobic threshold, provide increased maximal oxygen intake and improve endurance by 8-10%. Recommended intakes of sodium during prolonged exercise sessions should be aimed at 300-600mg per hour or 1.7-2.9 during said session (Kerksick et al., 2018).
Vegetarian, Vegan, Lacto-ovo, and Pescatarian Athletes Considerations
Nutritional programing around plant based diets is a growing area, whether it is for personal reasons, perceived health benefits, a love for animals or environmental endeavors. Plant based diets are on the rise for young athletes with research showing approximately 2% of young athletes between the ages of 6-17years of age are following a vegetarian based diet, with another 6% following vegan based dieting practices of excluding all animal based foods (Barr & Rideout, 2004). Heavy plant based or exclusively plant based diets present a unique challenge for athletes in that the incidence of malabsorption or deficiency in vitamins and minerals such as zinc, iron, B12, the hormone vitamin D and iodine can not only affect performance but negatively impact the individual’s health status (Barr & Rideout, 2004). Female athletes suffering from disordered eating, amenorrhea and osteoporosis, the synergistic trio of symptoms known as the female athlete triad, have been found to be more likely among vegetarian dieters (Barr & Rideout, 2004).
Another consideration for plant based dieters should be the lower digestibility and bioavailability rate of plant based sources of protein. Lacto-ovo vegetarians, which include eggs and milk products in their diets, and pescatarians, whom consume fish and other seafood, are more likely to meet their protein needs (Whitney & Rolfes, 2005). Exclusive plant based vegan diets with RDA’s for protein may still be low in RDA’s for one or more of the sulfur containing amino acids or lysine, threonine and tryptophan (Barr & Rideout, 2004). In order to ensure optimal protein intake and amino acid intake, those practicing these dieting methods should aim to consume protein from a variety of plant sources including whole grains, seeds, nuts, legumes and vegetables (Whitney & Rolfes, 2005).
Use of Supplements
There exists a number of considerations to make regarding supporting the validity of supplement use, but outside of general recommendations it is always up to the consumer to fully educate themselves on a product or ingredient prior to its consumption. Supplement use in on the rise in the United States as evidenced by dietary supplement sales in 1994 from 4 billion to an increase of 33 billion by the year 2012 (Knapik, Steelman, Hoedebecke, Austin, Farina, & Lieberman, 2016). While there exists a large number of ingredients, blends, and formulas on the market purported to enhance training, expedite recovery, or improve performance, examination must be critical and use be limited to supplements which are supported in clinically validated amounts to optimize performance and most importantly supported by bias free literature (Kerksick et al., 2018). Athletes seeking to consume supplements should also consider the legality of the supplements use and whether or not it is banned by their respective athletic association and more importantly if it is banned, whether or not it is even safe to consume (Kerksick et al., 2018). Often times intrigued by the products marketing claims, athletes, especially younger athletes, may be more prone to use said supplements without careful consideration of both the short and long-term effects certain supplements, such as pro-hormones, may have. Finally, consumers should educate themselves and investigate whether or not there is any scientific literature supporting ergogenic claims made by the distributor and if so was the study reputable and have those findings been duplicated in other similar studies (Kerksick et al., 2018). As with any major dietary changes, all supplement usage should be discussed with a family practitioner prior to beginning any supplement regimen.
Fad Dieting
Considerations should also be made for athletes following “fad diets”. Identification of these practices is critical in helping athletes avoid detrimental practices, which may affect both their health and performance. “Fad diets” promote nutritionally unbalanced macronutrient distributions, excessively low caloric intakes, or schemes such as liquid consumptions or supplement cocktails as opposed to whole food consumption with promises of expedited weight loss and improved body composition (Whitney & Rolfes, 2005). Athletes should aim to avoid these diets as they are typically not supported through literature to be more effective for weight loss endeavors and can at times can carry adverse side effects due to the nutritional practices and recommendations and most importantly they more often than not fail to provide a sustainable model for weight management once the “diet” ends (Whitney & Rolfes, 2005).
In a study published in the International Journal of Sport Nutrition and Exercise Metabolism, Lis, Kings, and Larson-Meyer (2019) discuss how different diets are popular among track-and-field athletes. Like all athletes, dietary practices are utilized for those looking to benefit improvement in their sport. Certain fad diets of gluten-free, vegetarian, intermittent fasting, and low carb began as ways to help gastrointestinal issues pre-race, avoid food intolerances/allergies, lose weight, or allow for religious belief followings (Lis, Kings, & Larson-Meyer, 2019). However, while fad diets may help satisfy a specific short-term goal for athletes, most results are short-lived. Lis, Kings, and Larson-Meyer recommend that anyone who is following a fad diet be mindful of adequate macro and micro nutrient intake, fully educate and understand how different dietary practices may affect performance and health, and not to follow unnecessary dietary trends simply because others are doing it, as there are risks associated with inadequate nutrition.
Conclusion
In conclusion, dietary practices are necessary to obtain proper macro and micronutrient requirements. The mass variety of sources to obtain both macro and micronutrients should allow for athletes to choose foods that best suit not only the requirements, but also their taste or beliefs. Whether an athlete chooses to follow a specific diet or not, proper education and understanding of the necessity of macronutrients, vitamins, and minerals can allow athletes to remain in a good health standing and even improve performance.
Disclaimer
All programs and articles provided are intellectual property of James Shmagranoff. No copies or redistribution of these is allowed without express permission from James Shmagranoff. James Shmagranoff is not a doctor and nothing contained within this article is to be taken as medical advice. Always follow the directions of your medical practitioner.
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