A basic knowledge of nutrition principle is essential for individuals working with physical active individuals. We will presents fundamental information regarding the macronutrients (i.e., carbohydrate, protein, fat), highlights selected vitamins and minerals with specific regard for physical activity and human performance, and provides a basis for estimating energy requirements. Nutritional considerations for athletic performance and exercise are incorporated.
The major nutrients
There are two major classes of nutrients critical to the understanding of human nutrition:
Macronutrients and micronutrients.
Each class of nutrients has a vital role in optimising growth, development, and health status.
The nutrients are also vital for physical performance regardless of n individual’s training status. The macronutrients, carbohydrates, proteins, and fat are organic compounds that contain carbon, hydrogen, and oxygen. The macronutrients provide energy ( i.e., kilocalories), and respectively energy contents of these nutrients are listed below in the table. The macronutrients provide power ( i.e., kilocalories), and respectively energy contents of these nutrients are listed below in the table. Protein is unique, given it also contains nitrogen as a component of its constituent amino acid. Comply with this kind of relationship for more information about this topic.
| Micronutrients | Energy(kal/g) |
| Carbohydrate | 4 |
| Protein | 4 |
| Fat | 9 |
| alcohol | 7 |
Micronutrients include vitamins and minerals and are required in much lower quantities than macronutrients. In addition, micronutrients do not provide energy. Nonetheless, vitamins and minerals are critical to proper growth and metabolism.
List of the major vitamins and minerals are listed below in the table:
| Fat soluble | Major function | Dietary source |
| A | Maintenance of skin, bone, teeth, growth and vision | Carrots, broccoli, spinach, eggs, cheese, and milk |
| D | Maintenance and growth of bones | Milk, egg yolk, tuna , and salmon |
| E | Antioxidant | Vegetable oils, whole grains, green leafy |
| K | Blood clotting | Breen leafy vegetables, cabbage, and milk |
| Water soluble | Major function | Dietary sources |
| B1( thiamin) | Energy production | Bread, pasta, pork, oysters |
| B 2(riboflavin) | Energy production | Milk, meat, cereals, pasta, dark green vegetables |
| B3 (niacin) | Energy production | Poultry, meat, tuna, cereal , pasta, bread, nuts, legumes |
| B6( pyridoxine) | Protein and fat metabolism | Avocados, green beans, spinach , cereals, bread |
| B12(cobalamine ) | Red blood cell formation | Meat, fish, milk, eggs |
| Folic acid | DNA synthesis, red blood cell information | Dark green leafy vegetables, fortified cereals, wheat germ, oranges, bananas |
| Pantothenic acid | Macronutrients metabolism, hormone synthesis | Cereals, bread, nuts, eggs, dark green vegetables |
| C( ascorbic acid) | Antioxidants, maintenance of bones, teeth, collagen | Citrus fruits, melons, strawberries, tomatoes, green papers, potatoes |
| Biotin | Fatty acid synthesis, energy production | Egg yolk, green leafy vegetables |
The proper blend of nutrients is necessary for normal growth and development, as well as maintenance of health.
| Mineral | Major function | Dietary sources |
| Major minerals | ||
| Calcium | Growth, bone and teeth formation, nerve impulses | Diary, dark green vegetables, sardines, calms |
| Sodium | Body water and acid-base balance, nerve function | Abundant in most food |
| Potassium | Body water and acid-base balance, nerve function | Meat, milk, fruits, vegetables, cereals, legumes |
| Chloride | Acid-base balance | Table salt, seafood, meats, eggs, milk |
| Phosphorus | Bone and teeth formation, acid-base balance | Diary, meat, fish, poultry, nuts, grains |
| Trace minerals | ||
| Iron | Components of hemoglobin and enzymes | Meats, eggs, legumes, grains, dark green vegetables |
| Chromium | Glucose and energy metabolism | Fats, meats, cereals |
| Zinc | Component of enzymes | Milk, shellfish, wheat bran |
Carbohydrate
Carbohydrate, specifically glucose, is the preferred fuel source for the body and the nervous system. Carbohydrates are classified by the number of sugar molecules they contain and can be divided into either simple or complex carbohydrates. As an energy source, carbohydrate provides 4 kilocalories per gram.
Simple carbohydrates refer to monosaccharides (one sugar molecule) or disaccharides (two sugar molecules). The most common forms of monosaccharides include glucose, fructose, and galactose.
The most common disaccharides include sucrose, lactose, and maltose. Sucrose, more commonly referred to as table sugar, is composed of glucose and fructose and is found primarily in sugar cane, honey, and maple syrup.
Lactose is composed of glucose and galactose and is the sugar most commonly found in milk. Lastly, maltose, a disaccharide consisting of two glucose molecules, is a by-product of complex carbohydrate digestion, particularly starches, and is frequently present in various sports nutrition products.
Complex carbohydrates consist of three or more monosaccharides linked together. Depending on chain length, complex carbohydrates are called oligosaccharides or polysaccharides.
Oligosaccharides are between 3 and 10 monosaccharides in length and are found naturally in legumes, onions, and bananas. Polysaccharides are complex carbohydrates greater than ten monosaccharides in size. The most common polysaccharides are glycogen and starch. Glycogen, the storage form of glucose in humans, consists of numerous branched-chain of glucose molecules stored in the liver and skeletal muscle. When necessary, glycogen is easily broken down under conditions where glucose is needed. In particular, glycogen becomes the primary source of glucose for the exercising muscle during prolonged endurance exercise events.
Starches
Starches, the primary storage of carbohydrates in plants, are composed of either amylase, which consists of a straight chain of glucose molecules or amylopectin, which is made up of branched-chain glucose molecules. These starches are found in various food sources such as vegetables, legumes, wheat, and barley.
Fiber
Fibre is another type of complex carbohydrate. Fibres are not digested in the human body and therefore are not absorbed. However, fibre consumption can benefit health, including improved gastrointestinal health, glucose homeostasis, and enhanced satiety. In addition, fibre consumption has been linked to reduced cardiovascular disease risk by lowering hypertension and improving plasma cholesterol. Fibre has also been associated with a reduced risk of cancer.
Fibres are classified based on their solubility in water. Water-soluble and water-insoluble fibres are present in varying amounts in all plant sources.
Insoluble fibres are derived from the cell walls of plants and include cellulose, hemicelluloses, and lignins. Insoluble fibres are commonly found in broccoli, carrots, green beans, celery, and potato skins. In addition, insoluble fibres are found in whole wheat, wheat bran, and flex seed lignins.
Insoluble fibres increase bulk, soften stool, and shorten intestinal transit time. In contrast, soluble fibres undergo metabolic processing via fermentation by bacteria in the large intestine. The end products of bacterial fermentation are gas and short-chain fatty acids, which can be absorbed. Soluble fibres, such as pectin, gums, and certain hemicelluloses, can be found within plant cells. These soluble fibres and psyllium are beneficial in reducing blood cholesterol levels. Dietary sources of soluble fibres include oats, apples, and beans.
Carbohydrate digestion and absorption
Digestion and absorption of carbohydrates is a well choreographed series of events that occur in the mouth, stomach, small intestine, and large intestine, along with a number of essential secretor organs.
Ultimately dietary carbohydrates are broken down into monosaccharieds; the sugar molecules are then transported across the intestine into the blood, where they are distributed to all the tissues in the body. Not all carbohydrates are digested and absorbed at the same rate within the intestine. The rate at which carbohydrate is absorbed and causes a rise in blood glucose level is known as the glycemic response.
Glycemic response and glycemic index
The glycemic response related to the rate at which carbohydrates are digested and absorbed, what extent they raise blood glucose, and for how long blood glucose remains elevated. This varies upon the type and amount of carbohydrate ingested, as well as the other nutrients with which the carbohydrate is consumed. Simple sugar, starches, and refined ( i.e., fiber has been removed) carbohydrates typically cause a greater glycemic response as reflected by a more rapid rise in blood glucose following their consumption. Unrefined carbohydrates, which contain fiber, take longer to be digested and absorbed and therefore cause a lower glycemic response. Protein and fat, when consumed in conjunction with carbohydrates, can decrease the rate of carbohydrate digestion and absorption and subsequent appearance of glucose in blood. The glycemic response of a specific food is calculated by its glycemic index. Glycemic index is a ranking of how food affects blood glucose in comparison to an equal amount of a reference carbohydrate such as white bread of glucose. The reference food is assigned a value of 100 and test foods are expressed relative to the test value. Food with glycemic indexes greater than or equal to 70 are considered high glycemic foods, whereas food with an index less than 55 are considered low glycemic foods.
Although the glycemic index can provide information regarding food sources effects on blood glucose, the glycemic index dose not predict the impact of consuming these food as a part of a mixed meal. In addition, the role of glycemic index with specific regard to glycogen replenishment after exercise continues to be debated.
Carbohydrate metabolism
Carbohydrates produce energy through adenosine triphosphate (ATP) through aerobic metabolism. One glucose molecule’s complete (i.e., aerobic) metabolism yields 38 ATP. The basic formula to describe this process is :
C6H12O6 + 6CO2 = 6CO2+6H2O+38 ATP
Glycemic response and glycemic index
Glycolysis is the first stage of glucose metabolism, which consists of a series of reactions involving highly regulated enzymes. Depending upon oxygen availability, glycolysis can be considered aerobic or anaerobic. In the presence of oxygen, pyruvate is converted to acetyl-CoA within the mitochondria, beginning the first stage of aerobic metabolism. However, when oxygen is limited, acetyl-CoA is not formed, and pyruvate is converted to lactate. Lactate is a metabolic waste product of anaerobic glucose metabolism.
Citric acid cycle and electron transport chain
During aerobic metabolism of glucose, acetyl-CoA produced from pyruvate within the mitochondria enters a series of reactions known as the citric acid cycle. During these reactions, the citric acid cycle generates two ATP molecules for each pyruvate formed from one glucose molecule. In addition, this process generates high-energy electrons via reduced cofactors, which are transported to the final stage of aerobic glucose metabolism, the electron transport chain.
The electron transport chain is the final step in aerobic glucose metabolism. It involves a series of molecules, mostly proteins, associated with the inner mitochondrial membrane , which accepts the high-energy electrons shuttled to the mitochondria produced via glycolysis and the citric acid cycle and passes them down the chain of molecules until they are combined with oxygen and water. During the passing of the electrons, the energy is conserved and used to generate ATP. The citric acid cycle and the electron chain are essential to all energy producing processes in the body. Utilization of the macronutrients for fuel is highly integrated, with the citric acid cycle being the primary point of convergence.
Gluconeogenesis and glycogenolysis
The maintenance of blood glucose
In conditions where blood glucose levels are low, such as fasting or low carbohydrate intake, many of the reactions of glycolysis are reversed to produce new blood glucose. The production of new glucose is referred to as gluconeogenesis. This process occurs primarily in the liver. The major substrates for gluconeogenesis are lactate, selected amino acids(i.e., alanine), and glycerol. Gluconeogenesis is highly regulated, mostly through the action of hormones such as insulin and glucagon.
Another source of glucose for the body is glycogen stored in the liver and muscle. Liver glycogenolysis supplies new blood glucose, whereas muscle glycogen is a source of glucose exclusive to the muscle. As glycogen stores decrease, adipose tissue is degraded, providing fatty acid as an alternative fuel and glycerol for the synthesis of glucose via gluconeogenesis. During an overnight fast, gluconeogenesis and glycogenelysis work synergistically to maintain blood glucose. However, after approximately 30 hours of fasting, liver glycogen is depleted ; therefore gluconeogenesis becomes the only source of new blood glucose.
Hormones and regulations of blood glucose
The regulation of blood glucose is mainly regulated via two key pancreatic hormones, insulin and glucagon. Insulin is released in response to an increase in blood glucose; it stimulate glucose uptake into cells and promotes glucose storage as glycogen in the liver. In muscles, insulin promotes glucose uptake for energy production and stimulate glycogen synthesis for energy storage in the muscles. The major role of insulin is to maintain glucose homeostasis by decreasing blood glucose levels after meal containing carbohydrates.
In the fasted state, blood glucose levels begin to decline. Low blood glucose levels stimulate the release of the glucagon, which stimulate the gluconeogenesis and glycogenolysis in the liver to increase blood glucose. In addition to glucagon, the hormone epinephrine promotes glucose production under increased energy demands. Overall, the role off glucagon and epinephrine are to increase blood glucose, whereas the primary action of insulin is to decrease blood glucose levels.
Fat
Fat, or lipid, is the most energy-dense macronutrient. Fats provide 9 kilocalories per gram_ more twice the energy content of both carbohydrate and protein. The most recognizable forms of fats in the diet are oils, butter, high-fat dairy products, and animal products. Although a negative perception often exists with regard to consumption of fat because of its implication in the development of cardiovascular diseases, some sources of dietary fats such as avocados, nuts , and certain oils confer many health benefits.
Fat is stored in the body in large amounts in adipose tissue. These fat stores represent a large energy reservoir utilized during resting conditions, certain modes of exercise, and during energy- restricted states(i.e., weight-loss diets). In addition to being a source of energy, fat serves many vital role in the human body such as insulation and protecting vital organs. Fats are necessary for the production of steroid hormones such as testosterone and estrogen.
The primary fats in both food and in the body are in the form of triglycerides and cholesterol. Depending on their chemical structure, fats are classified as either saturated or unsaturated fatty acids ( which include mono- and polyunsaturated fatty acid). Unsaturated fatty acids differ from saturated fatty acid : some carbon are not saturated with hydrogen and therefore contain carbon-carbon double bonds.
Unsaturated fatty acids are classified by the number of double bonds in the carbon chain, which can either be monosaturated ( one double bond) or polyunsaturated ( more than one) fatty acids. The most common dietary monounsaturated fatty acid, oleic acid, is found primarily in olive and canola oil. Linoleic acid, found in the corn, safflower, and soybean oils, is the most common polyunsaturated fatty acid in the diet.
Dietary fat provides the essential fatty acids( EFAs), linoleic and linolenic acids. The most common omega 3 fatty acids are alpha-linolenic acid, eicosapentaenoic acid (EPA), and docasahexaenoic acid (DHA), found in vegetable and fish oils. Linoleic acid, present in corn and safflower oil, and arachidonic acid, found in meat and fish, are the most common omiga6 fatty acid. These EFAs are required for growth, for healthy skin, and for producing elements of immune system. Although the body requires only small amounts of EFAs ( 2% to 3% of total energy), obtaining sufficient amounts may require consuming a diet containing at least 10% of total energy from fat because the proportion of fatty acids in the diet is small.
The properties of unsaturated fatty acids are also affected by the position of hydrogen atoms around the carbon-carbon double bond. In general, most unsaturated fatty acids have both hydrogen atoms on the same side of the double bond, referred to as a cis configuration. Other unsaturated fatty acids with hydrogen atoms on opposing sides on the double bond are in the trans configuration, more commonly referred to as trans fatty acids. Trans fatty acids are less commonly found in naturally occurring foods. However, through a process known as hydrogenation, unsaturated fatty acids are altered from the cis to trans configurations and become more saturated. Trans fatty acids have been shown to be deleterious to health by increasing the risk of coronary artery diseases(CAD) by negatively influencing blood cholesterol. It is now recommended that total intake not exceed approximately 3% of total energy intake.
Cholesterol is a waxy, fat-like substance found in foods of animal origin. It is found in the membranes of all cells and performs a number of essential anatomical and physiological functions; it is necessary for bile acid and steroid hormone formation. It is not found in plants or plant products. Cholesterol, produced by the liver, is transported in the blood by distinct particles containing both lipids and protein(i.e., lipoprotein). There are three major classes of lipoprotein: a- low- density lipoprotein (LDL), b- high density lipoprotein(HDL), and c- very-low density lipoprotein(VLDL). In general, the liver produces sufficient amounts of cholesterol to meet requirements. Therefore, dietary consumption is unnecessary. However, cholesterol is found in many food sources. Thus, recommendations regarding dietary cholesterol intake suggest consuming no more than 300mg per day. Although monitoring cholesterol intake is important, dietary saturated and trans fatty acids have a more substantial negative impact on blood cholesterol, a risk factor for CAD.
Fat digestion and absorption
The majority of fat digestion occurs in the small intestine. In the presence of fat, the small intestine release cholecytokinin , or CCK, a hormone that signals the release of bile acid from the gallbladder. Bile acids “ emulsify” dietary fat in the small intestine so there is effective mixing with fat- digestion enzymes in the small intestine, ultimately leaving triglycerides and diglycerides to monoglycerides , fatty acids, and glycerol fro absorption.
Short- and medium- chain fatty acids, along with glycerol, can be taken up directly by the intestine and enter the blood. Monglycerides and lon-chain fatty acids, however, are repackaged into micelles that are absorbed by the small intestine. In the intestinal cells, the micelles are repackaged into chylomicron (i.e., lipoprotein) and released into lymphatic system for eventual entry into the blood stream.
The lipoprotein, with the exception of the chylomicron, are produced in the liver for transport of triglycerides and cholesterol through the blood. VLDLs are a major carrier of triglycerides. LDLs are principally composed of cholesterol. The cholesterol transported by LDLs may be deposited in the arterial walls, contributing to atherosclerosis. The smallest group of lipoprotein, the HDLs, appears to be protective by carrying cholesterol to the liver for breakdown and excretion. Therefore, individuals with high levels of HDL, low levels of LDL, low total cholesterol, and low total cholesterol/HDL cholesterol ratio carry lower risk of CAD. the impact of fat consumed ( saturated vs. unsaturated vs. trans fatty acids ) on the in the metabolism
Fat and energy metabolism
During periods of excess energy intake, the body stores extra calories as fat in adipose tissue .calories from dietary fat have the most efficient and direct route to keep .age when energy intake is higher than energy expenditure (i.e., fasting). The body can utilise dietary fat to produce energy. During endurance exercise, the body uses stored fat as an energy source.
Sources of dietary protein and protein quality
Protein is abundant in meat and dairy products and it’s found in significant level in cereals, grain, nuts, and legumes. In addition, certain fruits(i.e., apples, blueberries, and apricots) and vegetables (i.e., green beans and asparagus) contain small amounts of protein. Protein quality is determined by both amino acid content and digestibility of the protein. Protein derived from plant foods are approximately 85% digestible; those in a mixed diet of meat products and refined carbohydrates are approximately 95% digestible. Protein quality also considered the “ completeness” of the dietary protein. Complete, or high quality proteins, contain all of the EAAs. Plants proteins are generally classified as incomplete and considered to be of less quality than animal protein. Plants do contain all of the amino acids, but in lower amounts than animal proteins. Thus, one needs to eat more of a plant protein sources t obtain adequate amounts of the amino acids, particularly the EEAs. In some cases, one must consume more than one source of plant protein to obtain a sufficient amount of the EAA. Grains tend t lake lysine, for example, and legumes tend to lake methionine. Consuming both plant protein sources simultaneously allow for complementary amino acid combinations( such as soybeans and rice, wheat bread and peanut butter, pinto beans and corn tortillas) so that sufficient amounts of EAAs are derived from the diet.
Protein
Of the macronutrients, protein is unique because of the nitrogen(N) content of its constituent amino acid. Similar to carbohydrate, protein provides 4 kilocalories per gram. When proteins are oxidized for energy purposes or when dietary intake exceeds recommended amounts. CO2 and water are produced, whereas the N component is (a)- incorporated into urea and eliminated from the body in urine or (b)- used in the synthesis of dispensable amino acids and other nitrogen-containing compounds in the body. Proteins are considered a required and vita nutrients that serves both structural and functional components of muscle, bone, tendons, and ligaments, proteins function as enzymes critical in energy producing reactions, hormone that regulate metabolism, transporter s of other critical nutrients , and as an energy source in energy-deprived conditions. The latter function is the least desirable for this particular macronutrient. Both dietary and body proteins are composed of amino acid, which are classified as either essential( indispensable) or nonessential( dispensable). Nonessential amino acids (NEAAs) are amino acids that can be made by the body, whereas essential amino acids (EAAs) cannot be synthesized in the body and therefore must be consumed in the diet. All amino acids are needed to maintain optimal protein utilization in the body such as health, growth and development, and tissue maintenance and repair are promoted.
The branched chain amino acids (BCAA: leucine, isoleucine, valine) are a unique class of essential amino acids used almost exclusively by skeletal muscle.
Defining fat intake
Fats are vital for numerous roles in the body, including energy production, a structural component of the cell membranes, and the production of steroid hormones. In addition, fats are necessary for the diet to absorb fat-soluble vitamins and essential fatty acids. Like carbohydrates and unlike protein, fats can be synthesised from endogenous nonfat precursors, reducing their necessity in the diet.
Recommendations for a healthy diet include limiting specific fat intakes and increasing complex, unrefined carbohydrates and fibre.
Sources of dietary protein and protein quality
Protein is abundant in meat, dairy products, cereals, grains, nuts, and legumes. In addition, certain fruits(i.e., apples, blueberries, and apricots) and vegetables (i.e., green beans and asparagus) contain small amounts of protein. Both amino acid content and digestibility of the protein determine protein quality. Proteins derived from plant foods are approximately 85% digestible; those in a mixed diet of meat products and refined carbohydrates are about 95% digestible. Protein quality is also considered the “completeness” of the dietary protein. Complete or high-quality proteins contain all of the EAAs. Plants proteins are generally classified as incomplete and assessed as having less quality than animal proteins. Plants have all amino acids but in lower amounts than animal proteins. Thus, one needs to eat more plant protein sources t obtain adequate amounts of amino acids, particularly the EEAs. In some cases, one must consume more than one source of plant protein to get a sufficient quantity of the EAA. Grains tend t lake lysine, for example, and legumes tend to lake methionine. Both plant protein sources simultaneously allow for complementary amino acid combinations( such as soybeans and rice, wheat bread and peanut butter, and pinto beans and corn tortillas) so that sufficient amounts of EAAs are derived from the diet.
Protein digestion, absorption, and utilization
Protein digestion begins in the stomach and completed in the intestine. Amino acids resulting from dietary protein degradation are absorbed in the intestine. Once amino acids have been absorbed, they become available to the body. Collectively, amino acids reside in various amino acid pools, from which they can be used for (a)- maintenance, synthesis, or repair of body proteins,(b)- synthesis of other nitrogen-containing compounds , and (c)- energy production.
Recommended protein intake
Protein for adults remains at 0.8 g of protein per kilogram body weight, or approximately 0.4 g of protein per pound.
The range of protein intakes for optimal protein utilization that span 10% to 35% of the total calories provided by the diet.
Alcohol
Although not a macronutrient.
Alcohol does provide 7 kilocalories per gram.
Alcohol is readily absorbed by simple diffusion along the gastrointestinal tract, with most absorption occurring in the small intestine. The rapid absorption of alcohol is responsible for deleterious effects on mental and physical function. Body weight, gender, the type of alcohol, the rate at which an alcoholic beverage is consumed, and the consumption of other food determine blood alcohol levels. The liver metabolises the majority of the alcohol. The remainder is lost in the urine or exhaled. Excess alcohol consumption can cause acute alcohol intoxication, malnutrition, and chronic diseases, particularly life damage. However, moderate consumption ( i.e., one and two drinks per day for women and men, respectively) of some alcoholic beverages, particularly red wine, may confer health benefits such as improved lipoprotein profiles and reduced risk of cardiovascular diseases.
The effect of alcohol consumption persists for up to 48 hours and compromises several factors related to athletic performance. Alcohol metabolism by the liver interferes with carbohydrate utilisation, ultimately interfering with glycogen synthesis and glucose metabolism. In addition, immune function, recovery from exercise or injury, and hydration status can be impaired with alcohol consumption. Therefore, athletes are discouraged from consuming alcohol during training or competition.
Vitamins
Vitamins are vital organic compounds not synthesized by the body and are essential for optimal growth, development, and the maintenance of health. These nutrients are required and must be provided in small amounts in the diet. Vitamins are classified based upon their solubility in water or fat. Water soluble vitamins include the B vitamins and C . there are no storage form of water soluble vitamins, making regular consumption important. Fat- soluble vitamins A,D,E, and K, however, are stored in adipose tissue and thus are not required in the diet.
Function of vitamins
Each vitamin, be it water- or fat-soluble, has a unique role and, in some cases, works synergistically with other vitamins to contribute to health and well-being. Vitamins are promoters and regulators of many body reactions, including energy-producing reactions( thiamin, riboflavin, niacin, B6, B12, biotin, and pantothenic acid). More specifically, the B vitamins, along with biotin and pantothenic acid, act as coenzymes that bind to enzymes to promote their activity and assure proper function in the metabolism of the macronutrients. Other important roles of vitamins include aiding in the visual processes ( vitamin A), blood clotting ( vitamin K), and protection of cellular oxidative damage ( antioxidants; vitamins E and C).
B complex vitamins
The B complex vitamins include thiamin, riboflavin, niacin, B6,B12, pantotenic acid, and folate. These vitamins can be further classified as having roles in energy production, red blood cell production, and amino acid metabolism.
Energy production
Several B vitamins are essential to energy production by the body. These include. These are thiamin, riboflavin, niacin, B6, biotin, and pantothenic acid. Thiamin, riboflavin, and niacin, in particular, are associated with cofactors that are integral to energy-producing pathways for the macronutrients. Biotin, B6, and B12 are coenzymes for various carboxylases involved in macronutrient metabolism.
Red blood cell production
Given the critical role that red blood cells serve in oxygen delivery throughout the body, inadequate intake of folate or B12 is associated with fatigue and compromised athletic performance. Folate and B12 are in red blood cell production. Deficiencies of either nutrient can lead to anaemia.
Amino acid metabolism
Vitamin B6 is required for amino acid metabolism. B6 is part of several enzyme systems that are involved in nitrogen metabolism. Therefore, this nutrient is essential to reactions required for protein utilisation as fuel and synthesis of nitrogen-containing compounds in the body.
Vitamin c
Consumption of vitamin C (i.e., food source or supplement) can simultaneously facilitate iron absorption. Vitamin C supplementation is widespread, given these nutrients’ roles in supporting the immune system and the healing process. Vitamin C is also a powerful antioxidant.
Fat-soluble vitamins
Fat-soluble vitamins( A, D, E, and K) are stored in body lipids. As a result, these nutrients can be toxic if taken in excess. Only vitamin E has a role specific to exercise and human performance as an antioxidant.
Minerals
Minerals are needed for numerous metabolic reactions and physiologic processes. Major minerals are found in the body in amounts greater than 5 g, whereas trace minerals include calcium, phosphorus, potassium, magnesium, sulfur, sodium, and chloride. Iron, zinc, copper, iodine, and chromium are common trace minerals also needed for normal body functions. Mineral salts, or electrolytes, such as sodium and chloride, are dissolved in water in the body. Water balance and electrolyte balance are closely linked. The most noted functions of sodium, chloride, and potassium are as electrolytes involved in the regulation of water balance by the body.
Calcium
Calcium is required for healthy bones and teeth, muscle contraction, nerve transmission, and blood clotting. The role of calcium in bone formation is well know. Low intake of dietary calcium results in calcium removal from the bone to maintain normal body processes. If low calcium intake persists, bone turnover is compromised and bone mass is reduced. Routine exercise, particularly weight-bearing exercise, enhances calcium utilization and maintenance of bone mass. Although it is important for men to consume adequate calcium, women appear to be at particular risk for poor calcium intakes that may ultimately increase risk of osteoporosis later in life.
Iron
Iron is one of the most highly regarded trace minerals given its role as a component of oxygen-carrying proteins, hemoglobin and myoglobin. Because hemoglobin carries oxygen in the body and myoglobin aids oxygen delivery in the muscle, iron is important for aerobic metabolism and endurance exercise performance. Iron is also a constituent of several of the enzymes that constitute the electron transport chain. Iron, has an essential role in energy production by the body.
Vitamins and mineral supplementation
Individual who restrict their total energy intake or consume a diet with limited dietary variety are at risk for insufficient vitamin and mineral intakes. These individuals would benefit from a multivitamin mineral supplement that provides the recommended amounts of these micronutrients. Consumption of multiple vitamin or mineral supplements should be discouraged given the potential for toxicities or altered metabolism of other vitamins and minerals.
Water balance
Approximately two-thirds of a person’s body weight is water. Water serves several functions in the body. These include carrying nutrients and waste products; maintaining the integrity of proteins and glycogen; participating in metabolic reactions; providing a medium for the nutrients; maintaining blood volume, blood pressure, and body temperature; and acting as a lubricant. However, imbalances in body water efficiently restores water balance by regulating water intake and excretion with various mechanisms.
Water or fluid, a balance consists of water intake and water excretion. In healthy individuals, thirst controls water intake. Although the thirst sensation can fall behind the body’s water needed, most individuals can stay adequately hydrated. Water sources for the body are liquids, food, and metabolic water. These sources can provide approximately 1.4 to 3.0 L of water daily.
Water is lost from the body as excretory products(i.e., urine and faeces) and sweat and through respiration—the kidney, which response to various hormones, primarily controls the water response of the body. Cumulative water losses daily of approximately 1.4 to 3.0 L antidiuretic hormone, or ADH, is released from the brain when the blood volume or blood pressure is too low, stimulating kidney resorption of water. When body water losses are increased, the associated decrease in blood volume and blood pressure elicits the release of aldosterone, which causes sodium and water retention by the kidneys.
Water balance is maintained when fluid intake from foods, liquids, and metabolism equals losses from the kidneys, skin, lungs, and faeces.